.. include:: autodoc_abbr_options_c.rst
.. _`apdx:options_c_alpha`:
Keywords by Alpha
=================
.. glossary::
:sorted:
ACTIVE (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| An array giving the number of active orbitals (occupied plus unoccupied) per irrep (shorthand to make MCSCF easier to specify than using RAS keywords)
* **Type**: array
* **Default**: No Default
BENCH (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Some codes (DFT) can dump benchmarking data to separate output files
* **Type**: integer
* **Default**: 0
CC_TYPE (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Algorithm to use for CC or CEPA computation (e.g., CCD, CCSD(T), CEPA(3), ACPF). See :ref:`Cross-module Redundancies ` for details.
* **Type**: string
* **Possible Values**: DF, CONV, CD
* **Default**: CONV
CI_TYPE (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Algorithm to use for CI computation (e.g., CID or CISD). See :ref:`Cross-module Redundancies ` for details.
* **Type**: string
* **Possible Values**: CONV
* **Default**: CONV
CUBEPROP_BASIS_FUNCTIONS (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| List of basis function indices for which cube files are generated (1-based). All basis functions computed if empty.
* **Type**: array
* **Default**: No Default
CUBEPROP_FILEPATH (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Directory to which to write cube files. Default is the input file directory.
* **Type**: string
* **Default**: No Default
CUBEPROP_ORBITALS (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| List of orbital indices for which cube files are generated (1-based, :math:`+` for alpha, :math:`-` for beta). All orbitals computed if empty.
* **Type**: array
* **Default**: No Default
CUBEPROP_TASKS (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Properties to compute. Valid tasks include: ``DENSITY`` - Da, Db, Dt, Ds ``ESP`` - Dt, ESP ``ORBITALS`` - Psi_a_N, Psi_b_N ``BASIS_FUNCTIONS`` - Phi_N ``LOL`` - LOLa, LOLb ``ELF`` - ELFa, ELFb
* **Type**: array
* **Default**: No Default
CUBIC_GRID_OVERAGE (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| CubicScalarGrid spatial extent in bohr [O_X, O_Y, O_Z]. Defaults to 4.0 bohr each.
* **Type**: array
* **Default**: No Default
CUBIC_GRID_SPACING (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| CubicScalarGrid grid spacing in bohr [D_X, D_Y, D_Z]. Defaults to 0.2 bohr each.
* **Type**: array
* **Default**: No Default
DF_BASIS_CC (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| The density fitting basis to use in coupled cluster computations.
* **Type**: string
* **Possible Values**: :ref:`basis string `
* **Default**: No Default
DOCC (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| An array containing the number of doubly-occupied orbitals per irrep (in Cotton order)
* **Type**: array
* **Default**: No Default
FREEZE_CORE (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Specifies how many core orbitals to freeze in correlated computations. ``TRUE`` will default to freezing the standard default number of core orbitals. For PSI, the standard number of core orbitals is the number of orbitals in the nearest previous noble gas atom. More precise control over the number of frozen orbitals can be attained by using the keywords |globals__num_frozen_docc| (gives the total number of orbitals to freeze, program picks the lowest-energy orbitals) or |globals__frozen_docc| (gives the number of orbitals to freeze per irreducible representation)
* **Type**: string
* **Possible Values**: FALSE, TRUE
* **Default**: FALSE
FROZEN_DOCC (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| An array containing the number of frozen doubly-occupied orbitals per irrep (these are not excited in a correlated wavefunction, nor can they be optimized in MCSCF. This trumps |globals__num_frozen_docc| and |globals__freeze_core|.
* **Type**: array
* **Default**: No Default
FROZEN_UOCC (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| An array containing the number of frozen unoccupied orbitals per irrep (these are not populated in a correlated wavefunction, nor can they be optimized in MCSCF. This trumps |globals__num_frozen_uocc|.
* **Type**: array
* **Default**: No Default
INTEGRAL_PACKAGE (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Integral package to use. If compiled with ERD support, ERD is used where possible; LibInt is used otherwise.
* **Type**: string
* **Possible Values**: ERD, LIBINT
* **Default**: ERD
LITERAL_CFOUR (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Text to be passed directly into CFOUR input files. May contain molecule, options, percent blocks, etc. Access through ``cfour {...}`` block.
* **Type**: string
* **Default**: No Default
MP2_TYPE (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Algorithm to use for MP2 computation. See :ref:`Cross-module Redundancies ` for details.
* **Type**: string
* **Possible Values**: DF, CONV, CD
* **Default**: DF
MP_TYPE (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Algorithm to use for MPn ( :math:`n>2` ) computation (e.g., MP3 or MP2.5 or MP4(SDQ)). See :ref:`Cross-module Redundancies ` for details.
* **Type**: string
* **Possible Values**: DF, CONV, CD
* **Default**: CONV
NUM_FROZEN_DOCC (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| The number of core orbitals to freeze in later correlated computations. This trumps |globals__freeze_core|.
* **Type**: integer
* **Default**: 0
NUM_FROZEN_UOCC (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| The number of virtual orbitals to freeze in later correlated computations.
* **Type**: integer
* **Default**: 0
PCM (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| PCM boolean for pcmsolver module
* **Type**: :ref:`boolean `
* **Default**: false
PRINT (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| The amount of information to print to the output file. 1 prints basic information, and higher levels print more information. A value of 5 will print very large amounts of debugging information.
* **Type**: integer
* **Default**: 1
PROPERTIES (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| List of properties to compute
* **Type**: array
* **Default**: No Default
PROPERTIES_ORIGIN (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Either :ref:`a set of 3 coordinates or a string ` describing the origin about which one-electron properties are computed.
* **Type**: array
* **Default**: No Default
PUREAM (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Do use pure angular momentum basis functions? If not explicitly set, the default comes from the basis set. **Cfour Interface:** Keyword translates into |cfour__cfour_spherical|.
* **Type**: :ref:`boolean `
* **Default**: true
QC_MODULE (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| When several modules can compute the same methods and the default routing is not suitable, this targets a module. ``CCENERGY`` covers CCHBAR, etc. ``OCC`` covers OCC and DFOCC.
* **Type**: string
* **Possible Values**: CCENERGY, DETCI, DFMP2, FNOCC, OCC
* **Default**: No Default
REL_BASIS (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Whether to uncontract the basis set in a dual basis calculation
* **Type**: string
* **Default**: No Default
RESTRICTED_DOCC (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| An array giving the number of restricted doubly-occupied orbitals per irrep (not excited in CI wavefunctions, but orbitals can be optimized in MCSCF)
* **Type**: array
* **Default**: No Default
RESTRICTED_UOCC (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| An array giving the number of restricted unoccupied orbitals per irrep (not occupied in CI wavefunctions, but orbitals can be optimized in MCSCF)
* **Type**: array
* **Default**: No Default
SOCC (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| An array containing the number of singly-occupied orbitals per irrep (in Cotton order). The value of |globals__docc| should also be set.
* **Type**: array
* **Default**: No Default
UNITS (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Units used in geometry specification
* **Type**: string
* **Possible Values**: BOHR, AU, A.U., ANGSTROMS, ANG, ANGSTROM
* **Default**: ANGSTROMS
WRITER_FILE_LABEL (GLOBALS)
:ref:`apdx:GLOBALS` |w---w| Base filename for text files written by PSI, such as the MOLDEN output file, the Hessian file, the internal coordinate file, etc. Use the add_str_i function to make this string case sensitive.
* **Type**: string
* **Default**: No Default
CACHELEVEL (ADC)
:ref:`apdx:ADC` |w---w| How to cache quantities within the DPD library
* **Type**: integer
* **Default**: 2
MEMORY (ADC)
:ref:`apdx:ADC` |w---w| The amount of memory available (in Mb)
* **Type**: integer
* **Default**: 1000
NEWTON_CONVERGENCE (ADC)
:ref:`apdx:ADC` |w---w| The convergence criterion for pole searching step.
* **Type**: :ref:`conv double `
* **Default**: 1e-7
NORM_TOLERANCE (ADC)
:ref:`apdx:ADC` |w---w| The cutoff norm of residual vector in SEM step.
* **Type**: :ref:`conv double `
* **Default**: 1e-6
NUM_AMPS_PRINT (ADC)
:ref:`apdx:ADC` |w---w| Number of components of transition amplitudes printed
* **Type**: integer
* **Default**: 5
POLE_MAXITER (ADC)
:ref:`apdx:ADC` |w---w| Maximum iteration number in pole searching
* **Type**: integer
* **Default**: 20
PR (ADC)
:ref:`apdx:ADC` |w---w| Do use the partial renormalization scheme for the ground state wavefunction?
* **Type**: :ref:`boolean `
* **Default**: false
REFERENCE (ADC)
:ref:`apdx:ADC` |w---w| Reference wavefunction type
* **Type**: string
* **Possible Values**: RHF
* **Default**: RHF
ROOTS_PER_IRREP (ADC)
:ref:`apdx:ADC` |w---w| The poles per irrep vector
* **Type**: array
* **Default**: No Default
SEM_MAXITER (ADC)
:ref:`apdx:ADC` |w---w| Maximum iteration number in simultaneous expansion method
* **Type**: integer
* **Default**: 30
AO_BASIS (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| The algorithm to use for the :math:`\left` terms
* **Type**: string
* **Possible Values**: NONE, DISK, DIRECT
* **Default**: NONE
CACHELEVEL (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| The amount of cacheing of data to perform
* **Type**: integer
* **Default**: 2
GAUGE (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| The type of gauge to use for properties
* **Type**: string
* **Default**: LENGTH
INTS_TOLERANCE (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| Minimum absolute value below which integrals are neglected.
* **Type**: :ref:`conv double `
* **Default**: 1e-14
ONEPDM (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| Do compute one-particle density matrix?
* **Type**: :ref:`boolean `
* **Default**: false
ONEPDM_GRID_CUTOFF (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| Cutoff (e/A^3) for printing one-particle density matrix values on a grid
* **Type**: double
* **Default**: 1.0e-30
ONEPDM_GRID_DUMP (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| Write one-particle density matrix on a grid to file opdm.dx
* **Type**: :ref:`boolean `
* **Default**: false
ONEPDM_GRID_STEPSIZE (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| Stepsize (Angstrom) for one-particle density matrix values on a grid
* **Type**: double
* **Default**: 0.1
OPDM_RELAX (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| Do relax the one-particle density matrix?
* **Type**: :ref:`boolean `
* **Default**: false
PROP_ALL (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| Compute non-relaxed properties for all excited states.
* **Type**: :ref:`boolean `
* **Default**: true
PROP_ROOT (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| Root number (within its irrep) for computing properties
* **Type**: integer
* **Default**: 1
PROP_SYM (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| The symmetry of states
* **Type**: integer
* **Default**: 1
REFERENCE (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| Reference wavefunction type
* **Type**: string
* **Default**: RHF
ROOTS_PER_IRREP (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| The number of electronic states to computed, per irreducible representation
* **Type**: array
* **Default**: No Default
XI (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| Do compute Xi?
* **Type**: :ref:`boolean `
* **Default**: false
ZETA (CCDENSITY)
:ref:`apdx:CCDENSITY` |w---w| Do use zeta?
* **Type**: :ref:`boolean `
* **Default**: false
ABCD (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Type of ABCD algorithm will be used
* **Type**: string
* **Possible Values**: NEW, OLD
* **Default**: NEW
ANALYZE (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do analyze T2 amplitudes
* **Type**: :ref:`boolean `
* **Default**: false
BCCD_MAXITER (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Convert ROHF MOs to semicanonical MOs
* **Type**: integer
* **Default**: 50
BRUECKNER_ORBS_R_CONVERGENCE (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Convergence criterion for Breuckner orbitals. The convergence is determined based on the largest :math:`T_1` amplitude. Default adjusts depending on |ccenergy__e_convergence|.
* **Type**: :ref:`conv double `
* **Default**: 1e-5
CACHELEVEL (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Cacheing level for libdpd governing the storage of amplitudes, integrals, and intermediates in the CC procedure. A value of 0 retains no quantities in cache, while a level of 6 attempts to store all quantities in cache. For particularly large calculations, a value of 0 may help with certain types of memory problems. The default is 2, which means that all four-index quantites with up to two virtual-orbital indices (e.g., :math:`\langle ij | ab \rangle>` integrals) may be held in the cache.
* **Type**: integer
* **Default**: 2
CACHETYPE (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Selects the priority type for maintaining the automatic memory cache used by the libdpd codes. A value of ``LOW`` selects a "low priority" scheme in which the deletion of items from the cache is based on pre-programmed priorities. A value of LRU selects a "least recently used" scheme in which the oldest item in the cache will be the first one deleted.
* **Type**: string
* **Possible Values**: LOW, LRU
* **Default**: LOW
CC_NUM_THREADS (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Number of threads
* **Type**: integer
* **Default**: 1
CC_OS_SCALE (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Coupled-cluster opposite-spin scaling value
* **Type**: double
* **Default**: 1.27
CC_SS_SCALE (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Coupled-cluster same-spin scaling value
* **Type**: double
* **Default**: 1.13
DIIS (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do use DIIS extrapolation to accelerate convergence?
* **Type**: :ref:`boolean `
* **Default**: true
E_CONVERGENCE (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Convergence criterion for energy. See Table :ref:`Post-SCF Convergence ` for default convergence criteria for different calculation types.
* **Type**: :ref:`conv double `
* **Default**: 1e-6
LOCAL (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do simulate the effects of local correlation techniques?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL_CPHF_CUTOFF (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Cutoff value for local-coupled-perturbed-Hartree-Fock
* **Type**: double
* **Default**: 0.10
LOCAL_CUTOFF (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Value (always between one and zero) for the Broughton-Pulay completeness check used to contruct orbital domains for local-CC calculations. See J. Broughton and P. Pulay, J. Comp. Chem. 14, 736-740 (1993) and C. Hampel and H.-J. Werner, J. Chem. Phys. 104, 6286-6297 (1996).
* **Type**: double
* **Default**: 0.02
LOCAL_METHOD (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Type of local-CCSD scheme to be simulated. ``WERNER`` selects the method developed by H.-J. Werner and co-workers, and ``AOBASIS`` selects the method developed by G.E. Scuseria and co-workers (currently inoperative).
* **Type**: string
* **Possible Values**: WERNER, AOBASIS
* **Default**: WERNER
LOCAL_PAIRDEF (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Definition of local pair domains, default is BP, Boughton-Pulay.
* **Type**: string
* **Possible Values**: BP, RESPONSE
* **Default**: BP
LOCAL_WEAKP (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Desired treatment of "weak pairs" in the local-CCSD method. A value of ``NEGLECT`` ignores weak pairs entirely. A value of ``NONE`` treats weak pairs in the same manner as strong pairs. A value of MP2 uses second-order perturbation theory to correct the local-CCSD energy computed with weak pairs ignored.
* **Type**: string
* **Possible Values**: NONE, NEGLECT, MP2
* **Default**: NONE
MAXITER (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Maximum number of iterations to solve the CC equations
* **Type**: integer
* **Default**: 50
MP2_AMPS_PRINT (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do print the MP2 amplitudes which are the starting guesses for RHF and UHF reference functions?
* **Type**: :ref:`boolean `
* **Default**: false
MP2_OS_SCALE (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| MP2 opposite-spin scaling value
* **Type**: double
* **Default**: 1.20
MP2_SS_SCALE (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| MP2 same-spin scaling value
* **Type**: double
* **Default**: 1.0/3.0
NEW_TRIPLES (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do use new triples?
* **Type**: :ref:`boolean `
* **Default**: true
NUM_AMPS_PRINT (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Number of important :math:`t_1` and :math:`t_2` amplitudes to print
* **Type**: integer
* **Default**: 10
PAIR_ENERGIES_PRINT (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do print MP2 and CCSD pair energies for RHF references?
* **Type**: :ref:`boolean `
* **Default**: false
PROPERTY (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| The response property desired. Acceptable values are ``POLARIZABILITY`` (default) for dipole-polarizabilities, ``ROTATION`` for specific rotations, ``ROA`` for Raman Optical Activity, and ``ALL`` for all of the above.
* **Type**: string
* **Possible Values**: POLARIZABILITY, ROTATION, MAGNETIZABILITY, ROA, ALL
* **Default**: POLARIZABILITY
REFERENCE (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Reference wavefunction type
* **Type**: string
* **Possible Values**: RHF, ROHF, UHF
* **Default**: RHF
RESTART (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do restart the coupled-cluster iterations from old :math:`t_1` and :math:`t_2` amplitudes? For geometry optimizations, Brueckner calculations, etc. the iterative solution of the CC amplitude equations may benefit considerably by reusing old vectors as initial guesses. Assuming that the MO phases remain the same between updates, the CC codes will, by default, re-use old vectors, unless the user sets RESTART = false.
* **Type**: :ref:`boolean `
* **Default**: true
R_CONVERGENCE (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Convergence criterion for wavefunction (change) in CC amplitude equations.
* **Type**: :ref:`conv double `
* **Default**: 1e-7
SCSN_MP2 (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do SCS-MP2 with parameters optimized for nucleic acids?
* **Type**: :ref:`boolean `
* **Default**: false
SCS_CCSD (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do spin-component-scaled CCSD
* **Type**: :ref:`boolean `
* **Default**: false
SCS_MP2 (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do spin-component-scaled MP2 (SCS-MP2)?
* **Type**: :ref:`boolean `
* **Default**: false
SEMICANONICAL (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Convert ROHF MOs to semicanonical MOs
* **Type**: :ref:`boolean `
* **Default**: true
SPINADAPT_ENERGIES (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do print spin-adapted pair energies?
* **Type**: :ref:`boolean `
* **Default**: false
T2_COUPLED (CCENERGY)
:ref:`apdx:CCENERGY` |w---w|
* **Type**: :ref:`boolean `
* **Default**: false
T3_WS_INCORE (CCENERGY)
:ref:`apdx:CCENERGY` |w---w| Do build W intermediates required for cc3 in core memory?
* **Type**: :ref:`boolean `
* **Default**: false
ABCD (CCEOM)
:ref:`apdx:CCEOM` |w---w| Type of ABCD algorithm will be used
* **Type**: string
* **Possible Values**: NEW, OLD
* **Default**: NEW
CACHELEVEL (CCEOM)
:ref:`apdx:CCEOM` |w---w| Cacheing level for libdpd governing the storage of amplitudes, integrals, and intermediates in the CC procedure. A value of 0 retains no quantities in cache, while a level of 6 attempts to store all quantities in cache. For particularly large calculations, a value of 0 may help with certain types of memory problems. The default is 2, which means that all four-index quantites with up to two virtual-orbital indices (e.g., :math:`\langle ij | ab \rangle>` integrals) may be held in the cache.
* **Type**: integer
* **Default**: 2
CACHETYPE (CCEOM)
:ref:`apdx:CCEOM` |w---w| The criterion used to retain/release cached data
* **Type**: string
* **Possible Values**: LOW, LRU
* **Default**: LRU
CC3_FOLLOW_ROOT (CCEOM)
:ref:`apdx:CCEOM` |w---w| Do turn on root following for CC3
* **Type**: :ref:`boolean `
* **Default**: false
CC_NUM_THREADS (CCEOM)
:ref:`apdx:CCEOM` |w---w| Number of threads
* **Type**: integer
* **Default**: 1
COLLAPSE_WITH_LAST (CCEOM)
:ref:`apdx:CCEOM` |w---w| Do collapse with last vector?
* **Type**: :ref:`boolean `
* **Default**: true
COMPLEX_TOLERANCE (CCEOM)
:ref:`apdx:CCEOM` |w---w| Complex tolerance applied in CCEOM computations
* **Type**: :ref:`conv double `
* **Default**: 1e-12
EOM_GUESS (CCEOM)
:ref:`apdx:CCEOM` |w---w| Specifies a set of single-excitation guess vectors for the EOM-CC procedure. If EOM_GUESS = ``SINGLES``, the guess will be taken from the singles-singles block of the similarity-transformed Hamiltonian, Hbar. If EOM_GUESS = ``DISK``, guess vectors from a previous computation will be read from disk. If EOM_GUESS = ``INPUT``, guess vectors will be specified in user input. The latter method is not currently available.
* **Type**: string
* **Possible Values**: SINGLES, DISK, INPUT
* **Default**: SINGLES
EOM_REFERENCE (CCEOM)
:ref:`apdx:CCEOM` |w---w| Reference wavefunction type for EOM computations
* **Type**: string
* **Possible Values**: RHF, ROHF, UHF
* **Default**: RHF
E_CONVERGENCE (CCEOM)
:ref:`apdx:CCEOM` |w---w| Convergence criterion for excitation energy (change) in the Davidson algorithm for CC-EOM. See Table :ref:`Post-SCF Convergence ` for default convergence criteria for different calculation types.
* **Type**: :ref:`conv double `
* **Default**: 1e-6
FULL_MATRIX (CCEOM)
:ref:`apdx:CCEOM` |w---w| Do use full effective Hamiltonian matrix?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL (CCEOM)
:ref:`apdx:CCEOM` |w---w| Do simulate the effects of local correlation techniques?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL_CUTOFF (CCEOM)
:ref:`apdx:CCEOM` |w---w| Value (always between one and zero) for the Broughton-Pulay completeness check used to contruct orbital domains for local-CC calculations. See J. Broughton and P. Pulay, J. Comp. Chem. 14, 736-740 (1993) and C. Hampel and H.-J. Werner, J. Chem. Phys. 104, 6286-6297 (1996).
* **Type**: double
* **Default**: 0.02
LOCAL_DO_SINGLES (CCEOM)
:ref:`apdx:CCEOM` |w---w|
* **Type**: :ref:`boolean `
* **Default**: true
LOCAL_FILTER_SINGLES (CCEOM)
:ref:`apdx:CCEOM` |w---w| Do apply local filtering to singles amplitudes?
* **Type**: :ref:`boolean `
* **Default**: true
LOCAL_GHOST (CCEOM)
:ref:`apdx:CCEOM` |w---w| Permit ghost atoms to hold projected atomic orbitals to include in the virtual space in local-EOM-CCSD calculations
* **Type**: integer
* **Default**: -1
LOCAL_METHOD (CCEOM)
:ref:`apdx:CCEOM` |w---w| Type of local-CCSD scheme to be simulated. ``WERNER`` selects the method developed by H.-J. Werner and co-workers, and ``AOBASIS`` selects the method developed by G.E. Scuseria and co-workers (currently inoperative).
* **Type**: string
* **Possible Values**: WERNER, AOBASIS
* **Default**: WERNER
LOCAL_PRECONDITIONER (CCEOM)
:ref:`apdx:CCEOM` |w---w| Preconditioner will be used in local CC computations
* **Type**: string
* **Possible Values**: HBAR, FOCK
* **Default**: HBAR
LOCAL_WEAKP (CCEOM)
:ref:`apdx:CCEOM` |w---w| Desired treatment of "weak pairs" in the local-CCSD method. A value of ``NEGLECT`` ignores weak pairs entirely. A value of ``NONE`` treats weak pairs in the same manner as strong pairs. A value of MP2 uses second-order perturbation theory to correct the local-CCSD energy computed with weak pairs ignored.
* **Type**: string
* **Possible Values**: NONE, MP2, NEGLECT
* **Default**: NONE
MAXITER (CCEOM)
:ref:`apdx:CCEOM` |w---w| Maximum number of iterations
* **Type**: integer
* **Default**: 80
NEW_TRIPLES (CCEOM)
:ref:`apdx:CCEOM` |w---w| Do use new triples?
* **Type**: :ref:`boolean `
* **Default**: true
NUM_AMPS_PRINT (CCEOM)
:ref:`apdx:CCEOM` |w---w| Number of important CC amplitudes to print
* **Type**: integer
* **Default**: 5
OVERLAP_CHECK (CCEOM)
:ref:`apdx:CCEOM` |w---w| Report overlaps with old excited-state wave functions, if * available, and store current wave functions for later use.
* **Type**: :ref:`boolean `
* **Default**: false
PROP_ROOT (CCEOM)
:ref:`apdx:CCEOM` |w---w| Root number (within its irrep) for computing properties. Defaults to highest root requested.
* **Type**: integer
* **Default**: 0
PROP_SYM (CCEOM)
:ref:`apdx:CCEOM` |w---w| Symmetry of the state to compute properties. Defaults to last irrep for which states are requested.
* **Type**: integer
* **Default**: 1
REFERENCE (CCEOM)
:ref:`apdx:CCEOM` |w---w| Reference wavefunction type
* **Type**: string
* **Possible Values**: RHF, ROHF, UHF
* **Default**: RHF
RESTART_EOM_CC3 (CCEOM)
:ref:`apdx:CCEOM` |w---w| Do restart from on-disk?
* **Type**: :ref:`boolean `
* **Default**: false
RHF_TRIPLETS (CCEOM)
:ref:`apdx:CCEOM` |w---w| Do form a triplet state from RHF reference?
* **Type**: :ref:`boolean `
* **Default**: false
ROOTS_PER_IRREP (CCEOM)
:ref:`apdx:CCEOM` |w---w| Number of excited states per irreducible representation for EOM-CC and CC-LR calculations. Irreps denote the final state symmetry, not the symmetry of the transition.
* **Type**: array
* **Default**: No Default
R_CONVERGENCE (CCEOM)
:ref:`apdx:CCEOM` |w---w| Convergence criterion for norm of the residual vector in the Davidson algorithm for CC-EOM.
* **Type**: :ref:`conv double `
* **Default**: 1e-6
SCHMIDT_ADD_RESIDUAL_TOLERANCE (CCEOM)
:ref:`apdx:CCEOM` |w---w| Minimum absolute value above which a guess vector to a root is added to the Davidson algorithm in the EOM-CC iterative procedure.
* **Type**: :ref:`conv double `
* **Default**: 1e-3
SEMICANONICAL (CCEOM)
:ref:`apdx:CCEOM` |w---w| Convert ROHF MOs to semicanonical MOs
* **Type**: :ref:`boolean `
* **Default**: true
SINGLES_PRINT (CCEOM)
:ref:`apdx:CCEOM` |w---w| Do print information on the iterative solution to the single-excitation EOM-CC problem used as a guess to full EOM-CC?
* **Type**: :ref:`boolean `
* **Default**: false
SS_E_CONVERGENCE (CCEOM)
:ref:`apdx:CCEOM` |w---w| Convergence criterion for excitation energy (change) in the Davidson algorithm for the CIS guess to CC-EOM.
* **Type**: :ref:`conv double `
* **Default**: 1e-6
SS_R_CONVERGENCE (CCEOM)
:ref:`apdx:CCEOM` |w---w| Convergence criterion for norm of the residual vector in the Davidson algorithm for the CIS guess to CC-EOM.
* **Type**: :ref:`conv double `
* **Default**: 1e-6
SS_SKIP_DIAG (CCEOM)
:ref:`apdx:CCEOM` |w---w| Do skip diagonalization of Hbar SS block?
* **Type**: :ref:`boolean `
* **Default**: false
SS_VECS_PER_ROOT (CCEOM)
:ref:`apdx:CCEOM` |w---w| SS vectors stored per root
* **Type**: integer
* **Default**: 5
T3_WS_INCORE (CCEOM)
:ref:`apdx:CCEOM` |w---w| Do build W intermediates required for eom_cc3 in core memory?
* **Type**: :ref:`boolean `
* **Default**: false
VECS_CC3 (CCEOM)
:ref:`apdx:CCEOM` |w---w| Vectors stored in CC3 computations
* **Type**: integer
* **Default**: 10
VECS_PER_ROOT (CCEOM)
:ref:`apdx:CCEOM` |w---w| Vectors stored per root
* **Type**: integer
* **Default**: 12
CACHELEVEL (CCHBAR)
:ref:`apdx:CCHBAR` |w---w| Cacheing level for libdpd governing the storage of amplitudes, integrals, and intermediates in the CC procedure. A value of 0 retains no quantities in cache, while a level of 6 attempts to store all quantities in cache. For particularly large calculations, a value of 0 may help with certain types of memory problems. The default is 2, which means that all four-index quantites with up to two virtual-orbital indices (e.g., :math:`\langle ij | ab \rangle>` integrals) may be held in the cache.
* **Type**: integer
* **Default**: 2
EOM_REFERENCE (CCHBAR)
:ref:`apdx:CCHBAR` |w---w| Reference wavefunction type for EOM computations
* **Type**: string
* **Default**: RHF
T_AMPS (CCHBAR)
:ref:`apdx:CCHBAR` |w---w| Do compute the Tamplitude equation matrix elements?
* **Type**: :ref:`boolean `
* **Default**: false
WABEI_LOWDISK (CCHBAR)
:ref:`apdx:CCHBAR` |w---w| Do use the minimal-disk algorithm for Wabei? It's VERY slow!
* **Type**: :ref:`boolean `
* **Default**: false
ABCD (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Type of ABCD algorithm will be used
* **Type**: string
* **Default**: NEW
AO_BASIS (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| The algorithm to use for the :math:`\left` terms
* **Type**: string
* **Possible Values**: NONE, DISK, DIRECT
* **Default**: NONE
CACHELEVEL (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Cacheing level for libdpd governing the storage of amplitudes, integrals, and intermediates in the CC procedure. A value of 0 retains no quantities in cache, while a level of 6 attempts to store all quantities in cache. For particularly large calculations, a value of 0 may help with certain types of memory problems. The default is 2, which means that all four-index quantites with up to two virtual-orbital indices (e.g., :math:`\langle ij | ab \rangle>` integrals) may be held in the cache.
* **Type**: integer
* **Default**: 2
DIIS (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Do use DIIS extrapolation to accelerate convergence?
* **Type**: :ref:`boolean `
* **Default**: true
LOCAL (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Do simulate the effects of local correlation techniques?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL_CPHF_CUTOFF (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Cutoff value for local-coupled-perturbed-Hartree-Fock
* **Type**: double
* **Default**: 0.10
LOCAL_CUTOFF (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Value (always between one and zero) for the Broughton-Pulay completeness check used to contruct orbital domains for local-CC calculations. See J. Broughton and P. Pulay, J. Comp. Chem. 14, 736-740 (1993) and C. Hampel and H.-J. Werner, J. Chem. Phys. 104, 6286-6297 (1996).
* **Type**: double
* **Default**: 0.02
LOCAL_FILTER_SINGLES (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Do apply local filtering to single de-excitation (\ :math:`\lambda 1` amplitudes?
* **Type**: :ref:`boolean `
* **Default**: true
LOCAL_METHOD (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Type of local-CCSD scheme to be simulated. ``WERNER`` (unique avaliable option) selects the method developed by H.-J. Werner and co-workers.
* **Type**: string
* **Default**: WERNER
LOCAL_PAIRDEF (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Definition of local pair domains
* **Type**: string
* **Default**: No Default
LOCAL_WEAKP (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Desired treatment of "weak pairs" in the local-CCSD method. The value of ``NONE`` (unique avaliable option) treats weak pairs in the same manner as strong pairs.
* **Type**: string
* **Default**: NONE
MAXITER (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Maximum number of iterations
* **Type**: integer
* **Default**: 50
NUM_AMPS_PRINT (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Number of important CC amplitudes per excitation level to print. CC analog to |detci__num_dets_print|.
* **Type**: integer
* **Default**: 10
PROP_ALL (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Compute unrelaxed properties for all excited states.
* **Type**: :ref:`boolean `
* **Default**: true
PROP_ROOT (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Root number (within its irrep) for computing properties
* **Type**: integer
* **Default**: 1
PROP_SYM (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| The symmetry of states
* **Type**: integer
* **Default**: 1
RESTART (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Do restart the coupled-cluster iterations from old :math:`\lambda_1` and :math:`\lambda_2` amplitudes?
* **Type**: :ref:`boolean `
* **Default**: false
ROOTS_PER_IRREP (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| The number of electronic states to computed, per irreducible representation
* **Type**: array
* **Default**: No Default
R_CONVERGENCE (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Convergence criterion for wavefunction (change) in CC lambda-amplitude equations.
* **Type**: :ref:`conv double `
* **Default**: 1e-7
SEKINO (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Do Sekino-Bartlett size-extensive model-III?
* **Type**: :ref:`boolean `
* **Default**: false
ZETA (CCLAMBDA)
:ref:`apdx:CCLAMBDA` |w---w| Do use zeta?
* **Type**: :ref:`boolean `
* **Default**: false
ABCD (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Type of ABCD algorithm will be used
* **Type**: string
* **Default**: NEW
ANALYZE (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Do analyze X2 amplitudes
* **Type**: :ref:`boolean `
* **Default**: false
CACHELEVEL (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Cacheing level for libdpd
* **Type**: integer
* **Default**: 2
DIIS (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Do use DIIS extrapolation to accelerate convergence?
* **Type**: :ref:`boolean `
* **Default**: true
GAUGE (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Specifies the choice of representation of the electric dipole operator. Acceptable values are ``LENGTH`` for the usual length-gauge representation, ``VELOCITY`` for the modified velocity-gauge representation in which the static-limit optical rotation tensor is subtracted from the frequency- dependent tensor, or ``BOTH``. Note that, for optical rotation calculations, only the choices of ``VELOCITY`` or ``BOTH`` will yield origin-independent results.
* **Type**: string
* **Possible Values**: LENGTH, VELOCITY, BOTH
* **Default**: LENGTH
LINEAR (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Do Bartlett size-extensive linear model?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Do simulate local correlation?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL_CPHF_CUTOFF (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Cutoff value for local-coupled-perturbed-Hartree-Fock
* **Type**: double
* **Default**: 0.10
LOCAL_CUTOFF (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Value (always between one and zero) for the Broughton-Pulay completeness check used to contruct orbital domains for local-CC calculations. See J. Broughton and P. Pulay, J. Comp. Chem. 14, 736-740 (1993) and C. Hampel and H.-J. Werner, J. Chem. Phys. 104, 6286-6297 (1996).
* **Type**: double
* **Default**: 0.01
LOCAL_FILTER_SINGLES (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Do apply local filtering to single excitation amplitudes?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL_METHOD (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Type of local-CCSD scheme to be simulated. ``WERNER`` (unique avaliable option) selects the method developed by H.-J. Werner and co-workers.
* **Type**: string
* **Default**: WERNER
LOCAL_PAIRDEF (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Definition of local pair domains
* **Type**: string
* **Default**: NONE
LOCAL_WEAKP (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Desired treatment of "weak pairs" in the local-CCSD method. The value of ``NONE`` (unique avaliable option) treats weak pairs in the same manner as strong pairs.
* **Type**: string
* **Default**: NONE
MAXITER (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Maximum number of iterations to converge perturbed amplitude equations
* **Type**: integer
* **Default**: 50
NUM_AMPS_PRINT (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Number of important CC amplitudes per excitation level to print. CC analog to |detci__num_dets_print|.
* **Type**: integer
* **Default**: 5
OMEGA (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Array that specifies the desired frequencies of the incident radiation field in CCLR calculations. If only one element is given, the units will be assumed to be atomic units. If more than one element is given, then the units must be specified as the final element of the array. Acceptable units are ``HZ``, ``NM``, ``EV``, and ``AU``.
* **Type**: array
* **Default**: No Default
PROPERTY (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| The response property desired. Acceptable values are ``POLARIZABILITY`` (default) for dipole-polarizabilities, ``ROTATION`` for specific rotations, ``ROA`` for Raman Optical Activity (``ROA_TENSOR`` for each displacement), and ``ALL`` for all of the above.
* **Type**: string
* **Possible Values**: POLARIZABILITY, ROTATION, ROA, ROA\_TENSOR, ALL
* **Default**: POLARIZABILITY
REFERENCE (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Reference wavefunction type
* **Type**: string
* **Default**: RHF
RESTART (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Do restart from on-disk amplitudes?
* **Type**: :ref:`boolean `
* **Default**: true
R_CONVERGENCE (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Convergence criterion for wavefunction (change) in perturbed CC equations.
* **Type**: :ref:`conv double `
* **Default**: 1e-7
SEKINO (CCRESPONSE)
:ref:`apdx:CCRESPONSE` |w---w| Do Sekino-Bartlett size-extensive model-III?
* **Type**: :ref:`boolean `
* **Default**: false
AO_BASIS (CCSORT)
:ref:`apdx:CCSORT` |w---w| The algorithm to use for the :math:`\left` terms
* **Type**: string
* **Possible Values**: NONE, DISK, DIRECT
* **Default**: NONE
CACHELEVEL (CCSORT)
:ref:`apdx:CCSORT` |w---w| Cacheing level for libdpd governing the storage of amplitudes, integrals, and intermediates in the CC procedure. A value of 0 retains no quantities in cache, while a level of 6 attempts to store all quantities in cache. For particularly large calculations, a value of 0 may help with certain types of memory problems. The default is 2, which means that all four-index quantites with up to two virtual-orbital indices (e.g., :math:`\langle ij | ab \rangle>` integrals) may be held in the cache.
* **Type**: integer
* **Default**: 2
EOM_REFERENCE (CCSORT)
:ref:`apdx:CCSORT` |w---w| Reference wavefunction type for EOM computations
* **Type**: string
* **Default**: RHF
INTS_TOLERANCE (CCSORT)
:ref:`apdx:CCSORT` |w---w| Minimum absolute value below which integrals are neglected.
* **Type**: :ref:`conv double `
* **Default**: 1e-14
KEEP_OEIFILE (CCSORT)
:ref:`apdx:CCSORT` |w---w| Do retain the input one-electron integrals?
* **Type**: :ref:`boolean `
* **Default**: false
KEEP_TEIFILE (CCSORT)
:ref:`apdx:CCSORT` |w---w| Do retain the input two-electron integrals?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL (CCSORT)
:ref:`apdx:CCSORT` |w---w| Do simulate the effects of local correlation techniques?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL_CORE_CUTOFF (CCSORT)
:ref:`apdx:CCSORT` |w---w| Local core cutoff value
* **Type**: double
* **Default**: 0.05
LOCAL_CPHF_CUTOFF (CCSORT)
:ref:`apdx:CCSORT` |w---w| Cutoff value for local-coupled-perturbed-Hartree-Fock
* **Type**: double
* **Default**: 0.10
LOCAL_CUTOFF (CCSORT)
:ref:`apdx:CCSORT` |w---w| Value (always between one and zero) for the Broughton-Pulay completeness check used to contruct orbital domains for local-CC calculations. See J. Broughton and P. Pulay, J. Comp. Chem. 14, 736-740 (1993) and C. Hampel and H.-J. Werner, J. Chem. Phys. 104, 6286-6297 (1996).
* **Type**: double
* **Default**: 0.02
LOCAL_DOMAIN_MAG (CCSORT)
:ref:`apdx:CCSORT` |w---w| Do generate magnetic-field CPHF solutions for local-CC?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL_DOMAIN_POLAR (CCSORT)
:ref:`apdx:CCSORT` |w---w| Do use augment domains with polarized orbitals?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL_DOMAIN_SEP (CCSORT)
:ref:`apdx:CCSORT` |w---w|
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL_FILTER_SINGLES (CCSORT)
:ref:`apdx:CCSORT` |w---w| Do apply local filtering to single excitation amplitudes?
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL_METHOD (CCSORT)
:ref:`apdx:CCSORT` |w---w| Type of local-CCSD scheme to be simulated. ``WERNER`` (unique avaliable option) selects the method developed by H.-J. Werner and co-workers.
* **Type**: string
* **Default**: WERNER
LOCAL_PAIRDEF (CCSORT)
:ref:`apdx:CCSORT` |w---w| Definition of local pair domains, unique avaliable option is BP, Boughton-Pulay.
* **Type**: string
* **Default**: BP
LOCAL_WEAKP (CCSORT)
:ref:`apdx:CCSORT` |w---w| Desired treatment of "weak pairs" in the local-CCSD method. The value of ``NONE`` (unique avaliable option) treats weak pairs in the same manner as strong pairs.
* **Type**: string
* **Default**: NONE
OMEGA (CCSORT)
:ref:`apdx:CCSORT` |w---w| Energy of applied field [au] for dynamic properties
* **Type**: array
* **Default**: No Default
PROPERTY (CCSORT)
:ref:`apdx:CCSORT` |w---w| The response property desired. The unique acceptable values is ``POLARIZABILITY`` for dipole-polarizabilitie.
* **Type**: string
* **Default**: POLARIZABILITY
REFERENCE (CCSORT)
:ref:`apdx:CCSORT` |w---w| Reference wavefunction type
* **Type**: string
* **Default**: RHF
SEMICANONICAL (CCSORT)
:ref:`apdx:CCSORT` |w---w| Convert ROHF MOs to semicanonical MOs
* **Type**: :ref:`boolean `
* **Default**: true
AO_BASIS (CCTRANSORT)
:ref:`apdx:CCTRANSORT` |w---w| The algorithm to use for the :math:`\left` terms
* **Type**: string
* **Possible Values**: NONE, DISK, DIRECT
* **Default**: NONE
CACHELEVEL (CCTRANSORT)
:ref:`apdx:CCTRANSORT` |w---w| Cacheing level for libdpd
* **Type**: integer
* **Default**: 2
DELETE_TEI (CCTRANSORT)
:ref:`apdx:CCTRANSORT` |w---w| Delete the SO two-electron integrals after the transformation?
* **Type**: :ref:`boolean `
* **Default**: true
REFERENCE (CCTRANSORT)
:ref:`apdx:CCTRANSORT` |w---w| Reference wavefunction type
* **Type**: string
* **Default**: RHF
SEMICANONICAL (CCTRANSORT)
:ref:`apdx:CCTRANSORT` |w---w| Force conversion of ROHF MOs to semicanonical MOs to run UHF-based energies
* **Type**: :ref:`boolean `
* **Default**: false
CC_NUM_THREADS (CCTRIPLES)
:ref:`apdx:CCTRIPLES` |w---w| Number of threads
* **Type**: integer
* **Default**: 1
REFERENCE (CCTRIPLES)
:ref:`apdx:CCTRIPLES` |w---w| Reference wavefunction type
* **Type**: string
* **Default**: RHF
SEMICANONICAL (CCTRIPLES)
:ref:`apdx:CCTRIPLES` |w---w| Convert ROHF MOs to semicanonical MOs
* **Type**: :ref:`boolean `
* **Default**: true
TRANSLATE_PSI4 (CFOUR)
:ref:`apdx:CFOUR` |w---w| Do translate set Psi4 options to their cfour counterparts.
* **Type**: :ref:`boolean `
* **Default**: true
CFOUR_ABCDTYPE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the way the :math:`\langle ab||cd \rangle` molecular orbital integrals are handled in post-MP2 calculations. STANDARD (= 0) uses directly the corresponding MO integrals and thus results in an algorithm which in particular for large-scale calculations results in excessive use of disk space (storage of all :math:`\langle ab||cd\rangle` integrals. AOBASIS (=2) uses an AO-based algorithm to evaluate all terms involving the :math:`\langle ab||cd\rangle` integrals and significantly reduces the amount of disk storage. The use of ABCDTYPE=AOBASIS is strongly recommended for all CC calculations up to CCSD(T) and has been implemented for energy, gradient, second-derivative, and excitation energy calculations.
* **Type**: string
* **Possible Values**: STANDARD, AOBASIS
* **Default**: STANDARD
CFOUR_ACTIVE_ORBI (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the active orbitals used in a TCSCF calculation and has to be used in combination with the keyword |cfour__cfour_core_orbitals|. The active orbitals are specified by either NIRREP or 2*NIRREP integers specifying the number of active orbitals of each symmetry type, where NIRREP is the number of irreducible representations in the computational point group. If there are no orbitals of a particular symmetry type a zero must be entered. For more information and an example see |cfour__cfour_occupation| .
* **Type**: array
* **Default**: No Default
CFOUR_ANHARMONIC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies treatment of anharmonc effects by calculating cubic and/or quartic force fields. VIBROT (=3) requests calculation of only those cubic constants of the form :math:`\phi_{nij}`, where n is a totally symmetric coordinate. These are sufficient to determine the vibration-rotation interaction constants needed to calculate vibrational corrections to rotational constants, but are *not* sufficient to generate the corresponding cubic constants of isotopologs that have a lower point-group symmetry (*i.e.* HOD isotopolog of water). VPT2 (=1, note that the old value CUBIC can be still used and is equivalent to VPT2) generates all cubic constants and all quartic constants apart from those of the form :math:`\phi_{ijkl}`, which is enough for: 1) generation of cubic constants of isotopologs (see manual entries associated with anharmonic calculations for an example); 2) calculation of vibrational energy levels with VPT2. This keyword also directs the program to analyze resonances and calculate intensities of one- and two-quantum transitions. FULLQUARTIC (=2) (not part of the public release) is largely self-explanatory; it directs the program to calculate all quartic constants. This is sufficient (but this has not been implemented) to generate the full quartic force field of all isotopologs.
* **Type**: string
* **Possible Values**: CUBIC, VPT2, FULLQUARTIC, VIBROT, OFF
* **Default**: OFF
CFOUR_ANH_ALGORITHM (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies which algorithm is used for |cfour__cfour_anharmonic| =VIBROT, VPT2, and FULLQUARTIC calculations. If STANDARD (=0) is chosen, then simply invoking ``xcfour`` will cause a complete job to be run with all second-derivative calculations being done in series. If PARALLEL (=1), then the job stops after the second-derivative calculation at the reference geometry and generates out all input geometries for the remaining calculation. These can be then processed in "parallel" (currently not recommended). Note that it is recommended to carry out all calculations with PARALLEL, even when the actual calculation is carried out in a sequential mode.
* **Type**: string
* **Possible Values**: STANDARD, PARALLEL
* **Default**: STANDARD
CFOUR_ANH_DERIVATIVES (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether the anharmonic force field is calculated using analytic gradients (=FIRST) or analytic Hessians (=SECOND).
* **Type**: string
* **Possible Values**: FIRST, SECOND
* **Default**: SECOND
CFOUR_ANH_STEPSIZE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Controls the stepsize used in anharmonic force field calculations. The value is specified in reduced normal coordinates, which are dimensionless. The actual stepsize used in the calculation is :math:`\times 10^6` the integer value specified.
* **Type**: integer
* **Default**: 50000
CFOUR_ANH_SYMMETRY (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether nonabelian symmetry is to be exploited in determining displacements for |cfour__cfour_anharmonic| =VIBROT or VPT2 calculations. If set to NONABELIAN (=0), maximum advantage will be taken of symmetry and the full set of cubic force constants will be generated from a skeleton set by application of the totally symmetric projection operator. If set to ABELIAN (=1), only the operations of the abelian subgroup will be exploited. Note: It is important to point out that the symmetrization currently works only for cubic constants. Therefore, if you require quartic force constants (for frequency calculations), you *must* use the ABELIAN option. Moreover, the latter work for only asymmetric tops and linear molecules.
* **Type**: string
* **Possible Values**: ABELIAN, NONABELIAN
* **Default**: ABELIAN
CFOUR_AO_LADDERS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Can be used to control the algorithm used by CFOUR when terms involving :math:`\langle ab||cd\rangle` molecular orbital integrals are calculated in the atomic orbital basis (see |cfour__cfour_abcdtype|). MULTIPASS (= 0) uses an approach where the AO integral file is read a number of times in order to ensure maximal vectorization and is usually the optimal strategy on supercomputers; SINGLEPASS (= 1) determines the contributions with only a single pass through the AO integrals, but at the cost of significantly reduced vectorization. In general, however, SINGLEPASS is definitely preferable on workstations with RISC architectures. (Default : MULTIPASS on all 64-bit machines (e.g., CRAY-YMP) ; SINGLEPASS on all 32-bit machines (e.g., IBM-RS6000, HP-735, SGI-Indigo, DEC alphastations)). SPARSE_AO (=2) uses a sparse matrix algorithm which first rearranges the integral matrix in order to get "well-occupied" and "very sparse" blocks. "Well-occupied" blocks will be multiplied by matrix multiplication while in "very sparse" blocks only the non-zero elements are considered. The computational time is further reduced using symmetrized and anti-symmetrized integral and amplitude matrices in the multiplication. Substantial saving is assumed if SPARSE_AO (=2) is used.
* **Type**: string
* **Possible Values**: MULTIPASS, SINGLEPASS
* **Default**: SINGLEPASS
CFOUR_AV_SCF (CFOUR)
:ref:`apdx:CFOUR` |w---w| Experimental Use! ON (=1) requests and averaged SCF over two states. So far only implemented for degenerate doublet-Pi states and used in conjunction with SOPERT.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_BASIS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the AO basis used in the calculation. One can either specify a basis known to CFOUR or via BASIS=SPECIAL (=0) requests an arbitrary basis (see non-standard basis-set input). However, the latter must be available in the supplied GENBAS file. As standard basis sets, currently the following are available. **Psi4 Interface:** Recommended to use instead |mints__basis| for larger basis set selection and greater flexibility. When |mints__basis| used, |cfour__cfour_spherical| is set appropriately.
* **Type**: string
* **Possible Values**: STO-3G, 3-21G, 4-31G, 6-31G, 6-31G*, 6-31G**, 6-311G, 6-311G*, 6-311G**, DZ, DZP, TZ, TZP, TZ2P, PVDZ, PVTZ, PVQZ, PV5Z, PV6Z, PCVDZ, PCVTZ, PCVQZ, PCV5Z, PCV6Z, AUG-PVDZ, AUG-PVTZ, AUG-PVTZ, AUG-PVQZ, AUG-PV5Z, AUG-PV6Z, D-AUG-PVDZ, D-AUG-PVTZ, D-AUG-PVQZ, D-AUG-PV5Z, D-AUG-PV6Z, cc-pVDZ, cc-pVTZ, cc-pVQZ, cc-pV5Z, cc-pV6Z, cc-pCVDZ, cc-pCVTZ, cc-pCVQZ, cc-pCV5Z, cc-pCV6Z, PWCVDZ, PWCVTZ, PWCVQZ, PWCV5Z, PWCV6Z, PwCVDZ, PwCVTZ, PwCVQZ, PwCV5Z, PwCV6Z, svp, dzp, tzp, tzp2p, qz2p, pz3d2f, 13s9p4d3f, WMR, ANO0, ANO1, ANO2, EVEN\_TEMPERED, SPECIAL
* **Default**: SPECIAL
CFOUR_BRUCK_CONV (CFOUR)
:ref:`apdx:CFOUR` |w---w| experimental use
* **Type**: integer
* **Default**: 4
CFOUR_BRUECKNER (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether Brueckner orbitals are to be determined for the specified CC method. OFF(=0) Brueckner orbitals are not to be determined, ON (=1) they are to be determined.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_CACHE_RECS (CFOUR)
:ref:`apdx:CFOUR` |w---w| The number of records held in the i/o cache used by the post-SCF programs. The maximum number of records which can be held is 100.
* **Type**: integer
* **Default**: 10
CFOUR_CALC_LEVEL (CFOUR)
:ref:`apdx:CFOUR` |w---w| Defines the level of calculation to be performed. **Psi4 Interface:** Keyword set from argument of computation command: CCSD if ``energy('c4-ccsd')``, *etc.* See :ref:`Energy (CFOUR) ` and :ref:`Gradient (CFOUR) `. for all available.
* **Type**: string
* **Possible Values**: SCF, HF, MBPT(2), MP2, MBPT(3), MP3, SDQ-MBPT(4), SDQ-MP4, MBPT(4), MP4, CCD, CCSD, CCSD(T), CCSDT-1, CCSDT-1b, CCSDT-2, CCSDT-3, CCSDT-4, CCSDT, CC2, CC3, QCISD, QCISD(T), CID, CISD, UCC(4), B-CCD
* **Default**: SCF
CFOUR_CC_CONV (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the convergence criterion for the CC amplitude equations. The amplitudes are considered to be converged when the maximum of all (absolute) changes in the amplitudes is less than :math:`10^N`, where :math:`N` is the value associated with the keyword.
* **Type**: integer
* **Default**: 7
CFOUR_CC_EXPORDER (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the maximum number of expansion vectors used in the iterative subspace to enhance convergence in the solution of the CC equations.
* **Type**: integer
* **Default**: 5
CFOUR_CC_EXTRAPOLATION (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the type of convergence acceleration used to solve the CC equations. RLE (=0) uses the RLE methods of Purvis and Bartlett, DIIS (=1) uses the DIIS approach by Pulay, NOJACOBI (=2) uses RLE with continuous extrapolation, OFF (=3) uses no convergence acceleration. In general, DIIS provides the best results and is recommended, while OFF often results in poor convergence and thus cannot be recommended.
* **Type**: string
* **Possible Values**: RLE, DIIS, NOJACOBI, OFF
* **Default**: DIIS
CFOUR_CC_MAXCYC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the maximum number of iterations in solving the CC amplitude equations.
* **Type**: integer
* **Default**: 50
CFOUR_CC_PROGRAM (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies which CC program is used. The available options are VCC (=0), ECC (=1), MRCC (=2), and EXTERNAL (=3). The default for all calculations is currently VCC which requests usage of ``xvcc``, but in many cases (e.g., for CCSD and CCSD(T)) ECC should be preferred due to the better performance of ``xecc`` (available currently for CCSD, CCSD+T, CCSD(T), and closed-shell CCSDT-n, CC3, and CCSDT). MRCC and External are intended for CC programs outside the CFOUR suite, e.g., the general CC module mrcc written by M. Kallay (Budapest, Hungary). Default: VCC Note: Using the option ECC is not recommended for ROHF gradients. That is, if you are doing a geometry optimization with ROHF as your reference wave function then it is safe to use the option VCC. **Psi4 Interface:** Keyword set according to best practice for the computational method |cfour__cfour_calc_level|, reference |cfour__cfour_reference| (NYI) and derivative level |cfour__cfour_deriv_level| according to Table :ref:`Best Practices ` when method specified by argument to computation command (*e.g.*, when ``energy('c4-ccsd')`` requested but not when ``energy('cfour')`` requested). Value can always be set explicitly.
* **Type**: string
* **Possible Values**: VCC, ECC, MRCC, EXTERNAL
* **Default**: VCC
CFOUR_CHARGE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the molecular charge. **Psi4 Interface:** Keyword set from active molecule.
* **Type**: integer
* **Default**: 0
CFOUR_CIS_CONV (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the convergence threshold as :math:`10^{-N}` for CIS calculations.
* **Type**: integer
* **Default**: 5
CFOUR_CONTINUUM (CFOUR)
:ref:`apdx:CFOUR` |w---w| Signifies that one or more "continuum" orbitals should be added to the calculation. VIRTUAL and DVIRTUAL specify one or two orbital which should be initially unoccupied (in the SCF calculation), while OCCUPIED and DOCCUPIED specify one or two orbitals which should be initially occupied.
* **Type**: string
* **Possible Values**: NONE, VIRTUAL, DVIRTUAL, OCCUPIED, DOCCUPIED
* **Default**: NONE
CFOUR_CONTRACTION (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the contraction scheme used by the integral and integral derivative program. SEGMENTED (=0) uses a segmented contraction scheme; GENERAL (=1) uses a general contraction scheme, and UNCONTRACTED (=2) uses the corresponding uncontracted sets. Note that even for truly segmented basis sets, the integral programs run significantly faster in the GENERAL mode.
* **Type**: string
* **Possible Values**: SEGMENTED, GENERAL, UNCONTRACTED
* **Default**: GENERAL
CFOUR_CONVERGENCE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Identical to |cfour__cfour_geo_conv|.
* **Type**: integer
* **Default**: 4
CFOUR_COORDINATES (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the type of coordinates used in the input file ZMAT. Value INTERNAL (=0) means that the geometry is supplied in the usual Z-matrix format, while CARTESIAN (=1) means that the geometry is given in Cartesian coordinates. A third option is XYZINT (=2) for which a Z-matrix connectivity is defined, but with values of the internal coordinates defined implicitly by supplying Cartesian coordinates. Note that geometry optimizations are currently only possible for INTERNAL and XYZ2INT. **Psi4 Interface:** Keyword set from active molecule, always CARTESIAN. Above restrictions on geometry optimizations no longer apply.
* **Type**: string
* **Possible Values**: INTERNAL, CARTESIAN, XYZINT
* **Default**: INTERNAL
CFOUR_CORE_ORBITALS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the core orbitals used in a TCSCF calculation and has to be used in combination with the keyword |cfour__cfour_active_orbi|. The core orbitals are specified by either NIRREP or 2*NIRREP integers specifying the number of core orbitals of each symmetry type, where NIRREP is the number of irreducible representations in the computational point group. If there are no orbitals of a particular symmetry type a zero must be entered. For more information and an example see |cfour__cfour_occupation|.
* **Type**: array
* **Default**: No Default
CFOUR_CPHF_CONVER (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the convergence criterion for the iterative solution of the CPHF and Z-vector equations. The solutions are considered to be converged when the residual norm of the error vector falls below :math:`10^N`.
* **Type**: integer
* **Default**: 12
CFOUR_CPHF_MAXCYC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the maximum number of cycles allowed for the solution of the CPHF- and/or Z-vector equations.
* **Type**: integer
* **Default**: 64
CFOUR_CURVILINEAR (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether or not Hessian matrix is transformed (nonlinearly) to curvilinear internal coordinates. A value of 0 (or OFF) turns the transformation off if the analytic force constants are not available, while it is always performed if CURVILINEAR=1 (or ON). Values higher than 1 (or NO) unconditionally turn the transformation off.(Default: ON if analytic Hessian is available, OFF otherwise).
* **Type**: :ref:`boolean `
* **Default**: true
CFOUR_DBOC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether the diagonal Born-Oppenheimer correction (DBOC) to the energy is evaluated (ON =1) or not (OFF =0). DBOC calculations are currently only available for HF-SCF and CCSD using RHF or UHF reference functions.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_DCT (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether the Dipole Coupling Tensor (DCT) is calculated (ON =1) or not (OFF =0).
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_DERIV_LEVEL (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether or not energy derivatives are to be calculated and if so whether first or second derivatives are computed. ZERO (= 0) derivatives are not calculated, FIRST (=1) first derivatives are calculated, SECOND (=2) second derivatives are calculated. Note that this keyword usually needs not be set in any calculation since it is automatically set if the appropriate other options in the CFOUR namelist are turned on. **Psi4 Interface:** Keyword set from type of computation command: ZERO if :py:func:`~driver.energy`, FIRST if :py:func:`~driver.gradient` or :py:func:`~driver.optimization`, *etc.*
* **Type**: string
* **Possible Values**: ZERO, FIRST, SECOND
* **Default**: ZERO
CFOUR_DIFF_TYPE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether orbital-relaxed (RELAXED =0) or orbital-unrelaxed (UNRELAXED =1) derivatives are computed in the CC calculation.
* **Type**: string
* **Possible Values**: RELAXED, UNRELAXED
* **Default**: RELAXED
CFOUR_DROPMO (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies which molecular orbitals will be dropped from the post-SCF calculation. The orbitals are numbered in ascending order from the most stable (negative energy) to the most unstable (largest positive energy). Individual orbitals must be separated with a dash, while x>y means orbitals x through y inclusive. For example, the string ``1>10-55-58>64``, would result in orbitals 1,2,3,4,5,6,7,8,9,10,55,58,59,60,61,62,63 and 64 being dropped. For UHF calculations, the appropriate orbitals are deleted for both spin cases. No dropped virtual MOs are currently allowed for gradient or property calculations.
* **Type**: string
* **Default**: No Default
CFOUR_ECP (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether effective core potentials (pseudopotentials) are used (ON, =1) or not (OFF, =0).
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_EIGENVECTOR (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies which eigenvector of the totally symmetric part of the block-factored Hessian is to be followed uphill in a transition state search. Eigenvectors are indexed by their eigenvalues -- the lowest eigenvalue is 1, the next lowest is 2, etc. The default is 1, which should always be used if you are not looking for a specific transition state which you know corresponds to motion along a different mode. In the future, relatively sophisticated generation of a guessed eigenvector will be implemented, but this is the way things are for now. Of course, this keyword has no meaning if |cfour__cfour_method| is not set to TS.
* **Type**: integer
* **Default**: 1
CFOUR_EL_ANHARM (CFOUR)
:ref:`apdx:CFOUR` |w---w| Experimental use, ON = 1 requests the evaluation of electrical anharmonicities
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_EOM_NONIT (CFOUR)
:ref:`apdx:CFOUR` |w---w| Controls whether non-iterative triples corrections are applied after various types of EOM-CCSD calculation. Works with |cfour__cfour_excite| set to EOMIP, might work with EOMEE, certainly doesn't work with EOMEA. Use with great caution, preferably after having a few drinks.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_ESTATE_CONV (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the threshold used in converging CC-LR/EOM-CC calculations. The iterative diagonalization is continued until the RMS residual falls below :math:`10^{-N}` with :math:`N` as the value specified with this keyword.
* **Type**: integer
* **Default**: 5
CFOUR_ESTATE_MAXCYC (CFOUR)
:ref:`apdx:CFOUR` |w---w| The maximum number of expansion vectors used in the solution of EOMCC equations (Default: 20, hard-coded to 4 in triples calculations)
* **Type**: integer
* **Default**: 20
CFOUR_ESTATE_PROP (CFOUR)
:ref:`apdx:CFOUR` |w---w| This keyword applies only to EOM-CC calculations and specifies whether any excited or ionized state one-electron properties are to be calculated. Proper use of this keyword requires a relatively advanced knowledge of quantum chemistry and the available options are discussed here. The options are: OFF (=0) [no properties or transition moments are calculated]; EXPECTATION (=1) [transition moments and dipole strengths are calculated along with selected one-electron properties which are evaluated as expectation values]; UNRELAXED (=2) [selected one-electron properties are calculated in an approximation that neglects relaxation of molecular orbitals]; RESPONSE (=3) [selected one-electron properties are calculated as analytic first derivatives of the energy]. Except for EOMCC calculations on two-electron systems (which are exact), properties obtained by the three approaches will not be equivalent. The default value for this keyword is slightly complicated. For TDA calculations, the default is EXPECTATION since the evaluation of transition moments involves only a negligible amount of additional computation relative to the evaluation of the excitation energies. For EOMCC, the default is OFF since evaluation of any transition moments or properties requires approximately twice the computational time. Transition moments and dipole strengths are evaluated by default for all values of ESTATE_PROP other than OFF.
* **Type**: string
* **Possible Values**: OFF, EXPECTATION, UNRELAXED, RESPONSE
* **Default**: No Default
CFOUR_ESTATE_SYM (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the number of excited states which are to be determined in each irreducible representation of the computational subgroup. The program attempts to find all of the lowest roots, but this is not guaranteed because the eigenvalue problem is not solved by direct matrix diagonalization, but rather by an iterative (modified Davidson) algorithm. For excited state gradient calculations, only one root (clearly) is used. In such a case, one and only one non-zero entry in the string can be used, and this value is usually set to one (*i.e.* 0/1/0/0). (However sometimes one wants to calculate the gradient for, say, the second root of a given symmetry, and in such a case, one could use 0/2/0/0. What happens is that both roots are calculated, but only the second one is used in the subsequent density matrix and gradient calculation.) The format used for this keyword is identical to that used in |cfour__cfour_occupation|. For example, for a computational subgroup having four symmetry species, the string 3/1/0/2 specifies that 6 total roots should be searched for, three in the first block, one in the second block, and two in the fourth block. It is also important to note that the ``%excite*`` input, if present, takes precedence over this keyword. Default: All zeros.
* **Type**: array
* **Default**: No Default
CFOUR_ESTATE_TRANS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether just the excitation energies (OFF, =0) or in addition transition moments (EXPECTATION, =1) are calculated. Note that this keyword should not be used in excited-state calculations involving analytic gradients and that transition moments are essentially only available for EOM-CCSD/CCSD-LR.
* **Type**: string
* **Possible Values**: OFF, EXPECTATION
* **Default**: OFF
CFOUR_EVAL_HESS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Tells the program, in the course of a geometry optimization, to calculate the Hessian explicitly every N cycles. 0 means never calculated explicitly. **Psi4 Interface:** Geometry optimizations run through PSI (except in sandwich mode) use PSI's optimizer and so this keyword has no effect. Use :ref:`optking ` keywords instead, particularly |optking__full_hess_every|.
* **Type**: integer
* **Default**: 0
CFOUR_EXCITATION (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies in CC calculations using mrcc the excitation level if the calculation level has been chosen as CC(n), CI(n), or CCn(n).
* **Type**: integer
* **Default**: 0
CFOUR_EXCITE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the type of EOM-CC/LR-CC treatment to be performed. Available options are NONE (=0), EOMEE (=3, the EOM-CC/CC-LR approach for the treatment of excited states), EOMIP (=4, the EOM-CC/CC-LR approach for the treatment of ionized states), EOMEA (=7, the EOM-CC/CC-LR approach for the treatment of electron-attached states).
* **Type**: string
* **Possible Values**: NONE, EOMEE, EOMIP, EOMEA
* **Default**: NONE
CFOUR_FC_FIELD (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the strength of a Fermi-Contact pertubation as required for finite-field calculations of spin densities and the FC contributions to indirect spin-spin coupling constants. The value must be specified as an integer and the FC strength used by the program will be the value of the keyword :math:`\times 10^{-6}`. The atom for which the FC perturbation is switched on is specified in the ZMAT file after the CFOUR command line and potential basis set input, as follows %spin density N with N as the number of atom (in (X5,I3) format) in the order they are written by JODA to the MOL file. Be aware that for some atoms, the calculation has to be run in lower symmetry or even without symmetry. (Default : 0)
* **Type**: integer
* **Default**: 0
CFOUR_FD_CALCTYPE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the algorithm used to compute the harmonic force constants in finite-difference calculations.GRADONLY (=0) evaluates the force constants and dipole moment derivatives by numerical differentiation of analytic gradients; ENERONLY (=1) evaluates the force constants by second differences of energies (dipole moment derivatives are not evaluated); while MIXED (=2) evaluates 1x1 blocks of symmetry-blocked force constants by second differences pf energies and all other elements by first differences of gradients. the GRADONLY and MIXED approaches may, of course, only be used hwen using computational methods for which analytic gradients are available.
* **Type**: string
* **Possible Values**: GRADONLY, ENERONLY, MIXED
* **Default**: GRADONLY
CFOUR_FD_IRREPS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Requests that only vibrational frequencies of certain symmetry types are evaluated in a VIBRATION=FINDIF calculation. The numbers of the irreducible representations for which vibrational analysis is to be performed are separated by slashes. For example, FD_IRREP=1/3/4 means compute the frequencies of modes transforming as the first, third, and fourth irreducible representations. If a symmetry is specified for which there are no vibrational modes, the program will terminate. The labels of the irreducible representations for this keyword are not usually the same as those used in the rest of the calculation. Moreover, for some point groups, for example, those of linear molecules, the two sets of labels refer to different subgroups. There is as yet no straightforward way to determine what they will be without starting a calculation. If one runs the ``xjoda`` and then the ``xsymcor`` executables, the relevant irreducible representations will be listed. If all vibrational frequencies are desired, this keyword need not be included. Default : compute vibrational frequencies for all irreducible representations
* **Type**: array
* **Default**: No Default
CFOUR_FD_PROJECT (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether or not rotational degrees of freedoms are projected out from the symmetry-adapted coordinates in a finite difference calculations. ON (=0) uses rotationally projected coordinates, while OFF (=1) retains the rotational degrees of freedom. At a stationary point on the potential energy surface, both options will give equivalent harmonic force fields, but OFF should be used at non-stationary points.
* **Type**: string
* **Possible Values**: ON, OFF
* **Default**: ON
CFOUR_FD_STEPSIZE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the step length in mass-weighted coordinates (in :math:`10^{-4} amu^{1/2} bohr` ) used in generating the force constant matrix by finite difference of Cartesian gradients.
* **Type**: integer
* **Default**: 5
CFOUR_FD_USEGROUP (CFOUR)
:ref:`apdx:CFOUR` |w---w| In finite difference calculations using the FINDIF option, this keyword specifies the point group to be used in generating the symmetry-adapted vibrational coordinates. FULL (= 0) specifies the full molecular point group, COMP (= 1) specifies the Abelian subgroup used in the electronic structure calculation.
* **Type**: string
* **Possible Values**: FULL, COMP
* **Default**: FULL
CFOUR_FILE_RECSIZ (CFOUR)
:ref:`apdx:CFOUR` |w---w| This specifies the physical length (in integer words) of the records used in the word-addressable direct access files used by CFOUR. This value should always be chosen as a multiple of 512 bytes, as your local system manager certainly understands.
* **Type**: integer
* **Default**: 2048
CFOUR_FILE_STRIPE (CFOUR)
:ref:`apdx:CFOUR` |w---w| This option allows the splitting of files. Input is required in the form N1/N2/N3/N4/N5, where N1, N2, N3, N4, and N5 specify the number of files in which ``MOINTS``, ``GAMLAM``, ``MOABCD``, ``DERINT``, and ``DERGAM`` are splitted, respectively.
* **Type**: string
* **Default**: 0/0/0/0/0
CFOUR_FINITE_PERTURBATION (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the field strength for a perturbation (defined within a ``%perturbation`` section). The value must be given as an integer, and the field strength used by the program will be then the value of the keyword :math:`\times 10^{-6}`.
* **Type**: integer
* **Default**: 0
CFOUR_FOCK (CFOUR)
:ref:`apdx:CFOUR` |w---w| This option is used to control the algorithm used for construction of the Fock matrix in SCF calculations. PK (=0) uses the PK-supermatrix approach while AO (=1) constructs the matrix directly from the basis function integrals. In general, PK is somewhat faster, but results in considerable use of disk space when out-of-core algorithms are required. (Default: FOCK).
* **Type**: string
* **Possible Values**: PK, AO
* **Default**: No Default
CFOUR_FREQ_ALGORITHM (CFOUR)
:ref:`apdx:CFOUR` |w---w| FREQ_ALGORIT experimental use
* **Type**: string
* **Possible Values**: STANDARD, PARALLEL
* **Default**: STANDARD
CFOUR_FROZEN_CORE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether in the correlation treatment all electron (OFF =0) or only the valence electrons (ON =1) are considered. This keyword provides an alternative to the |cfour__cfour_dropmo| keyword, as it allows frozen-core calculation without explicitly specifying the corresponding inner-shell orbitals.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_FROZEN_VIRT (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether in the correlation treatment all virtual orbitals (OFF =0) or only a subset of virtual orbitals (ON =1) are used. In the latter case, the threshold for deleting virtual orbitals based on the orbital energey needs to be specified in a ``%frozen_virt`` section.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_GAMMA_ABCD (CFOUR)
:ref:`apdx:CFOUR` |w---w| Used to control the handling and storage of two-particle density matrix elements with four virtual indices :math:`\Gamma(abcd)`. DISK (=0) directs the program to calculate and store all elements of :math:`\Gamma(abcd)`, while DIRECT (=1) tells the program to use alternative algorithms in which :math:`\Gamma(abcd)` is calculated and used "on the fly". Note that this option might be not available for all type of calculations.
* **Type**: string
* **Possible Values**: DISK, DIRECT
* **Default**: DISK
CFOUR_GENBAS_1 (CFOUR)
:ref:`apdx:CFOUR` |w---w| This keyword applies only to Hydrogen and Helium atoms and specifies the number of contracted Gaussian functions per shell. There is usually no need to use this keyword, but it can be useful for using a subset of the functions in a particular entry in the ``GENBAS`` file, particularly for generally contracted WMR basis sets. For example, if entry H:BASIS in the ``GENBAS`` file contains 7 contracted s functions, 4 p functions and a single d function, then setting GENBAS_1=730 would eliminate the last p function and the d function. Default: use the unaltered ``GENBAS`` entry.
* **Type**: string
* **Default**: No Default
CFOUR_GENBAS_2 (CFOUR)
:ref:`apdx:CFOUR` |w---w| This keyword performs the same function as |cfour__cfour_genbas_1| above, but applies to second-row atoms.
* **Type**: string
* **Default**: No Default
CFOUR_GENBAS_3 (CFOUR)
:ref:`apdx:CFOUR` |w---w| This keyword performs the same function as |cfour__cfour_genbas_1| and |cfour__cfour_genbas_2| , but applies to third-row atoms.
* **Type**: string
* **Default**: No Default
CFOUR_GENBAS_4 (CFOUR)
:ref:`apdx:CFOUR` |w---w| This keyword performs the same function as |cfour__cfour_genbas_1| , |cfour__cfour_genbas_2| , and |cfour__cfour_genbas_3| , but applies to fourth-row atoms.
* **Type**: string
* **Default**: No Default
CFOUR_GEO_CONV (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the convergence criterion for geometry optimization. The optimization terminates when the RMS gradient is below :math:`10^{-N}` Hartree/bohr, where :math:`N` is the specified value. **Psi4 Interface:** Geometry optimizations run through PSI (except in sandwich mode) use PSI's optimizer and so this keyword has no effect. Use :ref:`optking ` keywords instead, particularly |optking__g_convergence| =CFOUR, which should be equivalent except for different internal coordinate definitions.
* **Type**: integer
* **Default**: 5
CFOUR_GEO_MAXCYC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the maximum allowed number of geometry optimization cycles. **Psi4 Interface:** Geometry optimizations run through PSI (except in sandwich mode) use PSI's optimizer and so this keyword has no effect. Use :ref:`optking ` keywords instead, particularly |optking__geom_maxiter|.
* **Type**: integer
* **Default**: 50
CFOUR_GEO_MAXSTEP (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies largest step (in millibohr) which is allowed in geometry optimizations. **Psi4 Interface:** Geometry optimizations run through PSI (except in sandwich mode) use PSI's optimizer and so this keyword has no effect. Use :ref:`optking ` keywords instead, particularly |optking__intrafrag_step_limit|.
* **Type**: integer
* **Default**: 300
CFOUR_GEO_METHOD (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the used geometry optimization methods. The following values are permitted: NR (=0) --- straightforward Newton-Raphson search for minimum; RFA (=1) --- Rational Function Approximation search for minimum (this method can be used to find minima when the initial structure is in a region where the Hessian index is nonzero); TS (=2) Cerjan-Miller eigenvector following search for a transition state (can be started in a region where the Hessian index is not equal to unity); MANR (=3) --- Morse-adjusted Newton-Raphson search for minimum (very efficient minimization scheme, particularly if the Hessian is available); SINGLE_POINT (=5) for a single-point energy calculation. ENERONLY (=6) requests a geometry optimization based on single-point energy calculations. Default: SINGLE-POINT (NR as soon as variables are marked to be optimized).
* **Type**: string
* **Possible Values**: NR, RFA, TS, MANR, SINGLE\_POINT, ENERONLY
* **Default**: SINGLE\_POINT
CFOUR_GIAO (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether gauge-including atomic orbitals are used (ON) or not (OFF). Default: ON for |cfour__cfour_props| =NMR and =MAGNETIC, otherwise OFF
* **Type**: string
* **Possible Values**: ON, OFF
* **Default**: No Default
CFOUR_GRID (CFOUR)
:ref:`apdx:CFOUR` |w---w| Keyword used to control type of grid calculation (see later section in this manual). Options are OFF (=0), no grid calculation; CARTESIAN (=1), steps are in Cartesian coordinates (which must be run with |cfour__cfour_coordinates| =CARTESIAN); INTERNAL (=2), steps are in Z-matrix internal coordinates; QUADRATURE (=3) steps are chosen for an integration based on Gauss-Hermite quadrature. (Default: OFF)
* **Type**: string
* **Possible Values**: OFF, CARTESIAN, INTERNAL, QUADRATURE
* **Default**: OFF
CFOUR_GUESS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Where the initial SCF eigenvectors are read from. MOREAD means to read from the disk (the ``JOBARC`` file) and CORE means to use a core Hamiltonian initial guess. If MOREAD is chosen but no disk file is present, the core Hamiltonian is used. (Default: MOREAD)
* **Type**: string
* **Possible Values**: MOREAD, CORE
* **Default**: MOREAD
CFOUR_HBAR (CFOUR)
:ref:`apdx:CFOUR` |w---w| This keyword determines which action is taken by the linear response program. ON (=1) the full effective Hamiltonian is calculated and written to disk; OFF (=0) the "lambda" linear response equations are solved.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_HFSTABILITY (CFOUR)
:ref:`apdx:CFOUR` |w---w| Control analysis of the stability of RHF, ROHF and UHF wavefunctions, as well as a possible search for a lower SCF solution. There are three possible options for this keyword. OFF (=0) does nothing, while ON (=1) performs a stability analysis and returns the number of negative eigenvalues in the orbital rotation Hessian. A third option, FOLLOW (=2) performs the stability analysis and then proceeds to rotate the SCF orbitals in the direction of a particular negative eigenvalue of the orbital rotation Hessian (see the explanation of keyword |cfour__cfour_rot_evec|), after which the SCF is rerun.
* **Type**: string
* **Possible Values**: OFF, ON, FOLLOW
* **Default**: OFF
CFOUR_INCORE (CFOUR)
:ref:`apdx:CFOUR` |w---w| This keyword can be used to significantly reduce disk i/o, and should be implemented very soon. The following options are available: OFF (= 0), no special algorithms are used (the default case); ALL (=1) all quantities except the :math:`\langle ab\vert\vert cd\rangle` molecular integral lists are held in core; PARTIAL (= 2), the T2 and T1 vectors are held in core throughout the calculation; (=4) all quantities except the :math:`\langle ab\vert\vert cd\rangle` and :math:`\langle ab\vert\vert ci\rangle` integrals are held in core; (=5) :math:`\langle ij\vert\vert kl\rangle` and :math:`\langle ij\vert\vert ka\rangle` and two-index quantities are held in core; (=6) all direct access files (``MOINTS``, ``GAMLAM``, etc.) are held in core. At present, these options have been implemented only in the energy code ``xvcc`` and the excitation energy code ``xvee``. (Default: 0)
* **Type**: string
* **Possible Values**: OFF, ALL, PARTIAL
* **Default**: OFF
CFOUR_INPUT_MRCC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether an input for mrcc is written (ON, =0) or not (OFF, =1) if |cfour__cfour_cc_program| =EXTERNAL has been specified.
* **Type**: :ref:`boolean `
* **Default**: true
CFOUR_INTEGRALS (CFOUR)
:ref:`apdx:CFOUR` |w---w| This keyword defines what type of integral input will be written by ``xjoda``. VMOL (=1) has to be used with the programs of CFOUR. Using ARGOS (=0), input for Pitzer's ARGOS integral program will be written. (Default: VMOL).
* **Type**: string
* **Possible Values**: VMOL, ARGOS
* **Default**: VMOL
CFOUR_JODA_PRINT (CFOUR)
:ref:`apdx:CFOUR` |w---w| Controls amount of debug printing performed by ``xjoda``. The higher the number, the more information is printed. Values of 25 or higher generally do not produce anything of interest to the general user. Do not set JODA_PRINT to 999 as this will cause the core vector to be dumped to disk.
* **Type**: integer
* **Default**: 0
CFOUR_LINEQ_CONV (CFOUR)
:ref:`apdx:CFOUR` |w---w| Convergence threshold for linear equations controlled by LINEQ_TYPE. Equations are iterated until smallest residual falls below :math:`10^{-N}`, where :math:`N` is the value associated with this keyword.
* **Type**: integer
* **Default**: 7
CFOUR_LINEQ_MAXCY (CFOUR)
:ref:`apdx:CFOUR` |w---w| The maximum number of iterations in all linear CC equations.
* **Type**: integer
* **Default**: 50
CFOUR_LINEQ_TYPE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Determines the algorithm used to solve linear equations ( :math:`\Lambda` and derivative :math:`T` and :math:`\Lambda` ). POPLE (=0) uses Pople's method of successively orthogonalized basis vectors, while DIIS (=1) uses Pulay's DIIS method. The latter offers the practical advantage of requiring much less disk space, although it is not guaranteed to converge. Moreover, POPLE has not been tested for some time and should definitely be checked! (Default : DIIS)
* **Type**: string
* **Possible Values**: POPLE, DIIS
* **Default**: DIIS
CFOUR_LOCK_ORBOCC (CFOUR)
:ref:`apdx:CFOUR` |w---w| This keyword is used by the SCF program to determine if the orbital occupancy (by symmetry block) is allowed to change in the course of the calculation. ON (=1) locks the occupation to that set by the keyword |cfour__cfour_occupation| (or the initial guess if omitted); OFF (= 0) permits the occupation to change. (Default : 1 if the occupation is specified with |cfour__cfour_occupation| and for second and later steps of optimizations; 0 if |cfour__cfour_occupation| omitted.)
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_MAXSTEP (CFOUR)
:ref:`apdx:CFOUR` |w---w| Identical to |cfour__cfour_geo_maxstep|.
* **Type**: integer
* **Default**: 300
CFOUR_MEMORY_SIZE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the amount of core memory used in integer words (default) or in the units specified via the keyword |cfour__cfour_mem_unit|. Default: 100 000 000 (approximately 381 or 762 MB for 32 or 64 bit machines, respectively). **Psi4 Interface:** Keyword set in MB from memory input command when given.
* **Type**: integer
* **Default**: 100000000
CFOUR_MEM_UNIT (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the units in which the amount of requested core memory is given. Possible choices are INTEGERWORDS (default), kB, MB, GB, and TB. **Psi4 Interface:** Keyword set from memory input command when given, always MB.
* **Type**: string
* **Possible Values**: INTEGERWORDS, KB, MB, GB, TB
* **Default**: INTEGERWORDS
CFOUR_METHOD (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the geometry optimization strategy. Four values are permitted: NR (=0) -- Straightforward Newton-Raphson search for minimum; RFA (=1) -- Rational Function Approximation search for minimum (this method can be used to find minima when the initial structure is in a region where the Hessian index is nonzero); TS (=2) Cerjan-Miller eigenvector following search for a transition state (can be started in a region where the Hessian index is not equal to unity); MANR (=3) -- Morse-adjusted Newton-Raphson search for minimum (very efficient minimization scheme, particularly if the Hessian is available); 4 is currently unavailable; SINGLE_POINT (=5) is a single point calculation. **Psi4 Interface:** Geometry optimizations run through PSI (except in sandwich mode) use PSI's optimizer and so this keyword has no effect. Use :ref:`optking ` keywords instead, particularly |optking__opt_type| and |optking__step_type|.
* **Type**: string
* **Possible Values**: NR, RFA, TS, MANR, SINGLE\_POINT
* **Default**: SINGLE\_POINT
CFOUR_MRCC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the type of MRCC calculation. MK performs a MR-CC calculation based on Mukherjee's ansatz.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_MULTIPLICITY (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the spin multiplicity. **Psi4 Interface:** Keyword set from active molecule.
* **Type**: integer
* **Default**: 1
CFOUR_NACOUPLING (CFOUR)
:ref:`apdx:CFOUR` |w---w| Calculation of non-adiabatic coupling. In case of ON (=1) the method by Ichino, Gauss, Stanton is used to obtain the lambda coupling, while in case of LVC (=3) the lambda coupling is computed by means of the algorithm by Tajti and Szalay. Furthermore, NACV (=2) requests the computation of the full non-adiabatic coupling. Note that for calculations using LVC or NACV options the multiroot diagonalization has to be used, as requested via the keyword CFOUR_EOM_NSTATES (dne?) =MULTIROOT.
* **Type**: string
* **Possible Values**: ON, NACV, LVC
* **Default**: OFF
CFOUR_NEGEVAL (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies what to do if negative eigenvalues are encountered in the totally symmetric Hessian during an NR or MANR geometry-optimization search. If ABORT (=0), the job will terminate with an error message; if SWITCH (=1) the program will just switch the eigenvalue to its absolute value and keep plugging away (this is strongly discouraged!); and if RFA (=2), the keyword |cfour__cfour_geo_method| is switched to RFA internally and the optimization is continued. **Psi4 Interface:** Geometry optimizations run through PSI (except in sandwich mode) use PSI's optimizer and so this keyword has no effect. Use :ref:`optking ` keywords instead.
* **Type**: string
* **Possible Values**: ABORT, SWITCH, RFA
* **Default**: ABORT
CFOUR_NEWNORM (CFOUR)
:ref:`apdx:CFOUR` |w---w| All components of spherical AOâ€™s are normalized to 1. This feature can help with numerical convergence issues if AO integrals are involved. Currently only working for single-point energy calculations.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_NONHF (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether the reference function used in the correlation energy calculation satisfies the (spin-orbital) HF equations or not. Usually there is no need to set this parameter (OFF = 0 and ON =1), since standard non-HF reference functions (QRHF and ROHF) set this flag automatically.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_NTOP_TAMP (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies how many t amplitudes will be printed for each spin case and excitation level. For =N, The largest N amplitudes for each spin case and excitation level will be printed.
* **Type**: integer
* **Default**: 15
CFOUR_OCCUPATION (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the orbital occupanc of the reference function in terms of the occupation numbers of the orbitals and their irreducible representations. The occupancy is specified by either NIRREP or 2*NIRREP integers specifying the number of occupied orbitals of each symmetry type, where NIRREP is the number of irreducible representations in the computational point group. If there are no orbitals of a particular symmetry type a zero must be entered. If the reference function is for an open-shell system, two strings of NIRREP occupation numbers separated by a slash are input for the :math:`\alpha` and :math:`\beta` sets of orbitals. An example of the use of the OCCUPATION keyword for the water molecule would be OCCUPATION=3-1-1-0. For the :math:`^2A_1` water cation, an open-shell system, the keyword would be specified by OCCUPATION=3-1-1-0/2-1-1-0. It should be noted that the ``xvmol`` integral program orders the irreducible representations in a strange way, which most users do not perceive to be a logical order. Hence, it is usually advisable initially to run just a single point integral and HF-SCF calculation in order to determine the number and ordering of the irreducible representations. The occupation keyword may be omitted, in which case an initial orbital occupancy is determined by diagonalization of the core Hamiltonian. In many cases, HF-SCF calculations run with the core Hamiltonian guess will usually converge to the lowest energy HF-SCF solution, but this should not be blindly assumed. (Default: The occupation is given by the core Hamiltonian initial guess). **Psi4 Interface:** The arrays above are specified in PSI as (whitespace-tolerant) [3,1,1,0] and [[3,1,1,0],[3,0,1,0]].
* **Type**: array
* **Default**: No Default
CFOUR_OPEN-SHELL (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies which kind of open-shell CC treatment is employed. The default is a spin-orbital CC treatment (SPIN-ORBITAL =1) which is the only possible choice for UHF-CC schemes anyways. For ROHF-CC treatments, the possible options are beside the standard spin-orbital scheme a spin-restricted CC approach (SR-CC=3), as well as a corresponding linear approximation (which in the literature usually is referred to as partially-spin-adapted CC scheme) (PSA-CC=1). SR-CC and PSA-CC are within the CCSD approximation restricted to excitations defined by the first-order interacting space arguments. With the keywords PSA-CC_FULL (=2) or SR-CC_FULL (=6) inclusion of the so called "pseudo-triples" beyond the first-order interacting space is also possible. The two-determinant CC method for open-shell singlet states can be activated by TD-CC (=8).
* **Type**: string
* **Possible Values**: SPIN-ORBITAL, SR-CC, PSA-CC\_FULL, SR-CC\_FULL, TD-CC
* **Default**: SPIN-ORBITAL
CFOUR_OPT_MAXCYC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Identical to |cfour__cfour_geo_maxcyc|.
* **Type**: integer
* **Default**: 50
CFOUR_ORBITALS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the type of molecular orbitals used in post-HF calculations. STANDARD (=0) requests usage of the orbitals (from a corresponding HF-SCF calculation) without any modification. These are in the case of RHF/UHF the usual canonical HF orbitals and in the case of ROHF calculations the standard ROHF-orbitals with equal spatial parts for both the :math:`\alpha` and the :math:`\beta` spin orbitals. SEMICANONICAL (=1) forces in ROHF type calculations a transformation to so-called semicanonical orbitals which diagonalize the occupied-occupied and virtual-virtual blockes of the usual Fock-matrices. The use of semicanonical orbitals is, for example, required for ROHF-CCSD(T) calculations and for those calculations also automatically set. LOCAL requests a localization of the HF orbitals and this is currently done according to the Pipek-Mezey localization criterion. Note that it is strongly recommended not to use this keyword unless you know what are you doing. Default: STANDARD except for ROHF-CCSD(T) and ROHF-MP4 calculations for which SEMICANONICAL is the default.
* **Type**: string
* **Possible Values**: STANDARD, SEMICANONICAL
* **Default**: STANDARD
CFOUR_PERT_ORB (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the type of perturbed orbitals used in energy derivative calculations. STANDARD means that the gradient formulation assumes that the perturbed orbitals are not those in which the (perturbed) Fock matrix is diagonal. CANONICAL means that the perturbed orbitals are assumed to be canonical. This keyword is set automatically to CANONICAL in derivative calculations with methods which include triple excitations (MBPT[4]/MP4, CCSD+T[CCSD], CCSD[T], QCISD[T] and all iterative schemes like CCSDT-n and CC3) apart from CCSDT. IJ_CANONICAL requests a canonical perturbed-orbital treatment only for the occupied-occupied block of the unperturbed density matrix in analytic derivative calculations. For testing purposes, it is possible to force the use standard perturbed orbitals even in case of iterative triple excitations via the option FORCE_STANDA (dne?). Note also that in case of unrelaxed derivatives standard orbitals must be used. Default : STANDARD for all methods without triples (except CCSDT), CANONICAL for all methods with triples in case of relaxed derivatives.
* **Type**: string
* **Possible Values**: STANDARD, CANONICAL, IJ\_CANONICAL
* **Default**: No Default
CFOUR_POINTS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies either single (=1, or SINGLE) or double (=2, DOUBLE) sided numerical differentiation in the finite difference evaluation of the Hessian. Two-sided numerical differentiation is considerably more accurate than the single-sided method, and its use is strongly recommended for production work.
* **Type**: string
* **Possible Values**: SINGLE, DOUBLE
* **Default**: DOUBLE
CFOUR_PRINT (CFOUR)
:ref:`apdx:CFOUR` |w---w| Controls the amount of printing in the energy and energy derivative calculation programs. Using a value of 1 will produce a modest amount of additional output over the default value of 0, which includes some useful information such as SCF eigenvectors, Fock matrix elements, etc.
* **Type**: integer
* **Default**: 0
CFOUR_PROPS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether and which molecular property is calculated. OFF (=0) means that no property is calculated, FIRST_ORDER (=1) requests computation of various one-electron first-order properties (e.g., dipole moment, quadrupole moment, electric field gradient, spin densities,etc.), SECOND_ORDER (=2, in the next release replaced by STAT_POL) computes static electric polarizabilities, DYNAMICAL (=7, in the next release replaced by DYN_POL) requests the calculation of frequency-dependent polarizabilities (note that here an additional input of the frequency is required), NMR (=5) requests the calculation of NMR chemical shifts/chemical shielding tensors (by default using GIAOs), J_FC requests the calculation of the Fermi-Contact contribution to indirect spin-spin coupling constants, J_SD the calculation of the corresponding spin-dipole contribution, and J_SO the calculation of the corresponding spin-orbit contribution to J; HYPERPOL (=22) invokes a calculation of static hyperpolarizabilities, DYN_HYP (=23) requests the calculation of frequency-dependent hyperpolarizabilities, SHG (=24) the calculation of hyperpolarizabilities related to the second-harmonic generation, OPT_REC (=25) the computation of hyperpolarizabilities related to optical rectification, VERDET (=26) the calculation of Verdet constants.
* **Type**: string
* **Possible Values**: OFF, FIRST\_ORDER, SECOND\_ORDER, NMR, HYPERPOL, DYN\_HYP, SHG, OPT\_REC, VERDET
* **Default**: OFF
CFOUR_PROP_INTEGRAL (CFOUR)
:ref:`apdx:CFOUR` |w---w| Allows storage of property integrals computed in ``xvdint`` on internal files (e.g., ``MOINTS`` and ``GAMLAM``, default choice INTERNAL, =0) or on external files (EXTERNAL, =1).
* **Type**: string
* **Possible Values**: INTERNAL, EXTERNAL
* **Default**: INTERNAL
CFOUR_QRHFGUES (CFOUR)
:ref:`apdx:CFOUR` |w---w| If this keyword is set to ON (=1), then the QRHF orbitals specified by the |cfour__cfour_qrhf_general|, |cfour__cfour_qrhf_orbital| and CFOUR_QRHF_SPIN (nyi?) keywords are used as a starting guess for a restarted SCF procedure. This can be an extremely useful way to converge "difficult" SCF solutions, such as those that correspond to states that are not the lowest states of a given symmetry. Note that when this option is used, the calculation that is performed is not a QRHF-CC calcualtion; it is instead a UHF-based or ROHF-based calculation, depending on what type of reference is specified by the |cfour__cfour_reference| keyword. The QRHF aspect of the calculation is used simply as a device to converge the orbitals.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_QRHF_GENERAL (CFOUR)
:ref:`apdx:CFOUR` |w---w| The presence of this keyword specifies that a QRHF based CC calculation, or alternatively, an SCF calculation that uses the |cfour__cfour_qrhfgues| option, is to be performed.
* **Type**: array
* **Default**: No Default
CFOUR_QRHF_ORBITAL (CFOUR)
:ref:`apdx:CFOUR` |w---w| By default, in QRHF calculations, electrons are removed from the highest occupied orbital in a symmetry block (symmetry block HOMO), while electrons are added to the lowest unoccupied orbital within a symmetry block (symmetry block LUMO). The purpose of the QRHF_ORBITAL keyword is to allow additional flexibility in choosing which orbitals will have their occupation numbers altered. The value of this keyword gives the offset with respect to the default orbital for the orbital which will be depopulated (or populated) in QRHF-CC calculations. For calculations involving more than one removal or addition of electrons, values are separated by commas and correspond to the |cfour__cfour_qrhf_general| input on a one-to-one basis. For example, specifying |cfour__cfour_qrhf_general| =2/-4, QRHF_ORBITAL=3/2 means that an electron will be added to the third lowest virtual in symmetry block 2 and another will be removed from the second highest occupied orbital in symmetry block 4. Examples given later in this manual further illustrate the QRHF input options and may help to clarify any confusion resulting from this documentation. (Default : 1)
* **Type**: array
* **Default**: No Default
CFOUR_RAMAN_INT (CFOUR)
:ref:`apdx:CFOUR` |w---w| ON (=1) requests a calculation of Raman intensities based on the geometrical derivatives of the static polarizability tensor, while DYN (=2) requests a calculation of Raman intensities based on the derivatives of the dynamical polarizability tensor.
* **Type**: string
* **Possible Values**: ON, DYN, OFF
* **Default**: OFF
CFOUR_RAMAN_ORB (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether Raman intensities are calculated with orbital relaxation with respect to the electric field perturbation (RELAXED, = 1) or without orbital relaxation (UNRELAXED, = 0).
* **Type**: string
* **Possible Values**: RELAXED, UNRELAXED
* **Default**: UNRELAXED
CFOUR_RDO (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether or not relaxed density natural orbitals are to be computed. This option only has meaning for a correlated calculation. For =0, Do not compute. For =1, compute.
* **Type**: :ref:`boolean `
* **Default**: true
CFOUR_REFERENCE (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the type of SCF calculation to be performed. RHF (= 0) requests a restricted Hartree-Fock reference; UHF (= 1) an unrestricted Hartree-Fock reference; ROHF (= 2) a restricted open-shell Hartree-Fock calculation; TCSCF (=3) a two-configurational SCF calculation, and CASSCF (=4) a complete-active space SCF calculations (currently not implemented). **Psi4 Interface:** Keyword subject to translation from value of |scf__reference| unless set explicitly.
* **Type**: string
* **Possible Values**: RHF, UHF, ROHF, TCSCF, CASSCF
* **Default**: RHF
CFOUR_RELATIVISTIC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the treatment of relativistic effects. The default is a non-relativistic treatment (OFF), while perturbational treatments are invoked via MVD1 (mass-velocity and 1-electron Darwin conribution), MVD2 (mass-velocity and 1- and 2-electron Darwin contribution), DPT2 (second-order direct perturbation theory approach), SF-DPT4 (scalar-relativistic part of fourth-order direct perturbation theory, DPT4 (full fourth-order DPT including spin-orbit corrections), SF-DPT6 (scalar-relativistic part of sixth-order direct perturbation theory), SFREE (spin-free treatment), X2C1E (spin-free X2C-1e treatment), or DPT (synonym with DPT2).
* **Type**: string
* **Possible Values**: OFF, MVD1, MVd2, DPT2, SF-DPT4, DPT4, SF-DPT6, SFREE, X2C1E, DPT
* **Default**: OFF
CFOUR_RELAX_DENS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether the relaxed density matrix is computed for correlated wave functions. OFF (= 0) The relaxed density will not be computed, ON (= 1) it will be computed.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_RESTART_CC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Offers the possibilty to restart a CC calculation which stopped for various reasons, e.g. time limit, in the correlation part. However, note that a restart which is specified by ON (= 1) needs the following files of the previous unfinished calculation: ``JOBARC``, ``JAINDX``, ``MOINTS``, and ``MOABCD``.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_RES_RAMAN (CFOUR)
:ref:`apdx:CFOUR` |w---w| This option can be used to convert an analytically calculated gradient vector to a particular normal coordinate representation. A useful application is to calculate the gradient of an electronically excited state in the normal coordinate representation of the ground electronic state, as this provides a first approximation to resonance Raman intensities (hence the name of the keyword). Calculations that use the this option require the externally supplied force constant matrix ``FCMFINAL``, which is written to disk during the course of both analytic and finite-difference vibrational frequency calculations. No such transformation is performed if OFF (=0); while ON (=1) directs the program to evaluate the gradient and transform it to the chosen set of normal coordinates. A warning message is printed if the force constant matrix is unavailable.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_ROT_EVEC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies which eigenvector of the orbital rotation Hessian is to be used to rotate the original SCF orbitals. By default, it will use that associated with the lowest eigenvalue of the totally symmetric part of the block-factored Hessian, as this choice often leads to the lowest energy SCF solution. For RHF stability checks, only those instabilities which correspond to RHF solutions will be considered. It is important to understand that following non-symmetric eigenvectors lowers the symmetry of the wavefunction and that following RHF --> UHF stabilities leads to a UHF solution. To converge the SCF roots associated with such instabilities, one must run the calculation in reduced symmetry and as a closed-shell UHF case, respectively. Value *n* directs the program to follow the vector associated with the *n*\ th lowest eigenvalue having the proper symmetry (totally symmetric) and spin (RHF-->RHF or UHF-->UHF) properties. 0 means use the lowest eigenvalue.
* **Type**: integer
* **Default**: 0
CFOUR_SAVE_INTS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Tells CFOUR whether to delete large files (AO integrals and ``MOINTS`` file for now) when they are no longer needed. OFF (=0) They will not be saved, ON (=1) they will be saved.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_SCALE_ON (CFOUR)
:ref:`apdx:CFOUR` |w---w| Controls whether step scaling is based on the absolute step length (1-norm) (=0 or MAG(S)) or the largest individual step in the internal coordinate space (=1 or MAX(S)).
* **Type**: string
* **Possible Values**: MAG(S), MAX(S)
* **Default**: MAG(S)
CFOUR_SCF_CONV (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the convergence criterion for the HF-SCF equations. Equations are considered converged when the maximum change in density matrix elements is less than :math:`10^{-N}`. **Psi4 Interface:** Keyword subject to translation from value of |scf__d_convergence| unless set explicitly.
* **Type**: integer
* **Default**: 7
CFOUR_SCF_DAMPING (CFOUR)
:ref:`apdx:CFOUR` |w---w| Controls the damping (in the first iterations (specified by |cfour__cfour_scf_expstart| via :math:`D_{new} = D_{old} + X/1000 * (D_{new} - D_{old})` with :math:`X` as the value specified by the keyword. The default value is currently 1000 (no damping), but a value of 500 is recommended in particular for transition metal compounds where the SCF convergence is often troublesome. **Psi4 Interface:** Keyword subject to translation from value of |scf__damping_percentage| unless set explicitly.
* **Type**: integer
* **Default**: 1000
CFOUR_SCF_EXPORDER (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the number of density matrices to be used in the DIIS convergence acceleration procedure.
* **Type**: integer
* **Default**: 6
CFOUR_SCF_EXPSTART (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the first iteration in which the DIIS convergence acceleration procedure is applied.
* **Type**: integer
* **Default**: 8
CFOUR_SCF_EXTRAPOLATION (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether or not the DIIS extrapolation is used to accelerate convergence of the SCF procedure. OFF (=0) means do not use DIIS, ON (=1) means use DIIS.
* **Type**: :ref:`boolean `
* **Default**: true
CFOUR_SCF_MAXCYC (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the maximum number of SCF iterations. **Psi4 Interface:** Keyword subject to translation from value of |scf__maxiter| unless set explicitly.
* **Type**: integer
* **Default**: 150
CFOUR_SD_FIELD (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the strength of a spin-dipole pertubation as required for finite-field calculations of the SD contributions to indirect spin-spin coupling constants. The value must be specified as an integer and the SD strength used by the program will be the value of the keyword :math:`\times 10^{-6}`. (Default : 0, currently not implemented)
* **Type**: integer
* **Default**: 0
CFOUR_SPHERICAL (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether spherical harmonic (5d, 7f, 9g, etc.) or Cartesian (6d, 10f, 15g, etc.) basis functions are to be used. ON (= 1) uses spherical harmonics, OFF (= 0) uses Cartesians. **Psi4 Interface:** Keyword set according to basis design when |mints__basis| is used instead of |cfour__cfour_basis|. Keyword subject to translation from value of |globals__puream| unless set explicitly.
* **Type**: :ref:`boolean `
* **Default**: true
CFOUR_SPINROTATION (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether nuclear spin-rotation tensors are computed within a NMR chemical shift calculation (ON, =1) or not (OFF, =9). In the case of electronic g-tensor calculations for open-shell molecules this keyword controls the calculation of the electronic spin-rotation tensor.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_SPIN_FLIP (CFOUR)
:ref:`apdx:CFOUR` |w---w| Controls whether excitation energy calculations allow for a "spin flip" which changes the :math:`M_s` quantum number. Such calculations have some advantages for biradicals and are currently implemented (together with gradients) for CIS and CIS(D) calculations. Options are OFF and ON.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_SPIN_ORBIT (CFOUR)
:ref:`apdx:CFOUR` |w---w| Experimental Use! ON (=1) requests calculation of one-electron spin-orbit integrals. MEANSO additionally gives a mean-field treatment of the two-electron terms (spin-orbit mean field treatment as described Mol. Phys. 98, 1823-1833 (2000)).
* **Type**: string
* **Possible Values**: ON, MEANSO, OFF
* **Default**: OFF
CFOUR_SPIN_SCAL (CFOUR)
:ref:`apdx:CFOUR` |w---w| ON (=1) requests the spin-component scaled variant of the MP2 approach. This keyword has only an effect when |cfour__cfour_calc_level| =MP2 is specified and must be used together with |cfour__cfour_reference| =UHF.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_SUBGROUP (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies an Abelian subgroup to be used in a calculation. Acceptable arguments are DEFAULT (=0); C1 (= 1); C2 (= 2); CS (= 3); CI (= 4); C2V (= 5); C2H (= 6); D2 (= 7) and D2H (= 8). Use of C1 is of course equivalent to setting |cfour__cfour_symmetry| =OFF in the input. The DEFAULT option (which is the default) uses the highest order Abelian subgroup.
* **Type**: string
* **Possible Values**: DEFAULT, C1, C2, CS, CI, C2V, C2H, D2, D2H, OFF
* **Default**: DEFAULT
CFOUR_SYMMETRY (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies what subgroup of the full point group is to be used in the energy and/or gradient calculation (the computational point group). OFF (=1) forces a no symmetry run (in :math:`C_1` ) and ON (=0) runs the calculation in the largest self-adjoint subgroup ( :math:`D_{2h}` and its subgroups).
* **Type**: :ref:`boolean `
* **Default**: true
CFOUR_SYM_CHECK (CFOUR)
:ref:`apdx:CFOUR` |w---w| In principle can be used to force the SCF to converge a solution for which the density matrix transforms as the totally symmetric representation of the point group (i.e. no broken symmetry solutions). The code seems to work in most cases, but has currently been implemented for point groups with E type representation and not for those with triply-, quadruply- or pentuply-degenerate representations. Extending the code to those cases is probably straightforward, and the reader is encouraged to do so if (s)he is so inclined. SYM_CHECK=0 "forces" the high-symmetry solution. SYM_CHECK=OVERRIDE (=1) doesn't. The latter is the default.
* **Type**: :ref:`boolean `
* **Default**: true
CFOUR_T3_EXTRAPOL (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether the T3 amplitudes are included ON (=1) or not included OFF (=0) in the DIIS convergence acceleration during CCSDT calculations. Inclusion of T3 speeds up convergence and allows tight convergence, but on the other hand it increases disk space requirements. Note that this keyword is only available with module ``xecc``.
* **Type**: :ref:`boolean `
* **Default**: false
CFOUR_TAMP_SUM (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies how often the largest :math:`t` amplitudes are to be printed. For =0, amplitudes are printed at the beginning and end of the run. For =1, amplitudes are printed every iteration. For =2, amplitudes are printed every other iteration, etc.
* **Type**: integer
* **Default**: 5
CFOUR_THERMOCHEMISTRY (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether to calculate finite-temperature thermodynamic corrections after a frequency calculation. OFF (=0) skips this; ON (=1) gives abbreviated output; and VERBOSE (=2) gives elaborate output that is separated by translation, rotation and vibration. Default: ON (currently not available in public version)
* **Type**: string
* **Possible Values**: OFF, ON, VERBOSE
* **Default**: ON
CFOUR_TRANS_INV (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether or not translational invariance is exploited in geometrical derivative calculations. USE(=0) specifies that translational invariance is exploited, while IGNORE (=1) turns it off.
* **Type**: string
* **Possible Values**: USE, IGNORE
* **Default**: USE
CFOUR_TREAT_PERT (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether in a correlated NMR chemical shift calculations all perturbations are treated at once or sequentially. Available option are SIMULTANEOUS (=0) and SEQUENTIAL (=1). The latter is at least preferred for large-scale calculations, as it has less demands on the available disk space.
* **Type**: string
* **Possible Values**: SIMULTANEOUS, SEQUENTIAL
* **Default**: SIMULTANEOUS
CFOUR_UIJ_THRESHOLD (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the threshold value (given as an integer) for the treatment of CPHF coefficients in second derivative calculations using perturbed canonical orbitals. If a CPHF coefficient is above the threshold, the corresponding orbital rotation is treated (at the expense of additional CPU cost) using the standard non-canonical procedures, while orbital pairs corresponding to CPHF coefficients below the threshold are treated using perturbed canonical representation. Default: 25 (Default: 1 in the developer version)
* **Type**: integer
* **Default**: 25
CFOUR_UNITS (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the units used for molecular geometry input. ANGSTROM (= 0) uses Angstrom units, BOHR (= 1) specifies atomic units. **Psi4 Interface:** Keyword set from active molecule, always ANGSTROM.
* **Type**: string
* **Possible Values**: ANGSTROM, BOHR
* **Default**: ANGSTROM
CFOUR_UPDATE_HESSIAN (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether or not the Hessian update is carried out. OFF (= 0) uses the initial Hessian (however supplied, either the default guess or a ``FCMINT`` file), ON (= 1) updates it during subsequent optimization cycles. (not in current public version).
* **Type**: :ref:`boolean `
* **Default**: true
CFOUR_VIBRATION (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies whether (harmonic) vibrational frequencies are calculated or not. If the default NO (=0) is specified then no frequencies are calculated. For ANALYTIC, vibrational frequencies are determined from analytically computed second derivatives, and for FINDIF (=2) vibrational frequencies are calculated from a force field obtained by numerical differentiation of analytically evaluated gradients (or even single-point energies) using symmetry-adapted mass-weighted Cartesian coordinates. If vibrational frequencies are calculated, a normal mode analysis using the computed force-constant matrix is performed, rotationally projected frequencies are computed, infrared intensities are determined, and zero-point energies (ZPE) are evaluated.
* **Type**: string
* **Possible Values**: NO, ANALYTIC, FINDIF
* **Default**: NO
CFOUR_VTRAN (CFOUR)
:ref:`apdx:CFOUR` |w---w| This keyword defines what type of integral transformation is to be performed in the program ``xvtran``. FULL/PARTIAL (=0) allows the transformation program to choose the appropriate type of transformation, while FULL (=1) requires a full integral transformation and PARTIAL (=2) means a MBPT(2)-specific transformation where the :math:`(ab \vert cd)` integrals are not formed.
* **Type**: string
* **Possible Values**: FULL/PARTIAL, FULL, PARTIAL
* **Default**: FULL/PARTIAL
CFOUR_XFIELD (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the X-component of an external electric field. The value must be specified as an integer and the field used by the program will be the value of the keyword :math:`\times 10^{-6}`. This allows field strengths :math:`|\varepsilon| > 10^{-6}` to be used.
* **Type**: integer
* **Default**: 0
CFOUR_XFORM_TOL (CFOUR)
:ref:`apdx:CFOUR` |w---w| The tolerance for storing transformed integrals. Integrals less than :math:`10^{-N}` are neglected and not stored on disk.
* **Type**: integer
* **Default**: 11
CFOUR_YFIELD (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the Y-component of an external electric field. The value must be specified as an integer and the field used by the program will be the value of the keyword :math:`\times 10^{-6}`. This allows field strengths :math:`|\varepsilon| > 10^{-6}` to be used.
* **Type**: integer
* **Default**: 0
CFOUR_ZFIELD (CFOUR)
:ref:`apdx:CFOUR` |w---w| Specifies the Z-component of an external electric field. The value must be specified as an integer and the field used by the program will be the value of the keyword :math:`\times 10^{-6}`. This allows field strengths :math:`|\varepsilon| > 10^{-6}` to be used.
* **Type**: integer
* **Default**: 0
CIS_AD_STATES (CPHF)
:ref:`apdx:CPHF` |w---w| Which states to save AD Matrices for? * Positive - Singlets * Negative - Triplets *
* **Type**: array
* **Default**: No Default
CIS_AMPLITUDE_CUTOFF (CPHF)
:ref:`apdx:CPHF` |w---w| Minimum singles amplitude to print in CIS analysis
* **Type**: double
* **Default**: 0.15
CIS_DOPDM_STATES (CPHF)
:ref:`apdx:CPHF` |w---w| Which states to save AO difference OPDMs for? * Positive - Singlets * Negative - Triplets *
* **Type**: array
* **Default**: No Default
CIS_MEM_SAFETY_FACTOR (CPHF)
:ref:`apdx:CPHF` |w---w| Memory safety factor for allocating JK
* **Type**: double
* **Default**: 0.75
CIS_NO_STATES (CPHF)
:ref:`apdx:CPHF` |w---w| Which states to save AO Natural Orbitals for? * Positive - Singlets * Negative - Triplets *
* **Type**: array
* **Default**: No Default
CIS_OPDM_STATES (CPHF)
:ref:`apdx:CPHF` |w---w| Which states to save AO OPDMs for? * Positive - Singlets * Negative - Triplets *
* **Type**: array
* **Default**: No Default
CIS_TOPDM_STATES (CPHF)
:ref:`apdx:CPHF` |w---w| Which states to save AO transition OPDMs for? * Positive - Singlets * Negative - Triplets *
* **Type**: array
* **Default**: No Default
CPHF_MEM_SAFETY_FACTOR (CPHF)
:ref:`apdx:CPHF` |w---w| Memory safety factor for allocating JK
* **Type**: double
* **Default**: 0.75
CPHF_TASKS (CPHF)
:ref:`apdx:CPHF` |w---w| Which tasks to run CPHF For * Valid choices: * -Polarizability *
* **Type**: array
* **Default**: No Default
DEBUG (CPHF)
:ref:`apdx:CPHF` |w---w| The amount of debug information printed to the output file
* **Type**: integer
* **Default**: 0
DF_BASIS_SCF (CPHF)
:ref:`apdx:CPHF` |w---w| Auxiliary basis for SCF
* **Type**: string
* **Possible Values**: :ref:`basis string `
* **Default**: No Default
DO_QQR_SIEVE (CPHF)
:ref:`apdx:CPHF` |w---w| Do we do the QQR integral sieve of Maurer et al. When false, just uses * the Schwarz sieve.
* **Type**: :ref:`boolean `
* **Default**: false
DO_SINGLETS (CPHF)
:ref:`apdx:CPHF` |w---w| Do singlet states? Default true
* **Type**: :ref:`boolean `
* **Default**: true
DO_TRIPLETS (CPHF)
:ref:`apdx:CPHF` |w---w| Do triplet states? Default true
* **Type**: :ref:`boolean `
* **Default**: true
EXPLICIT_HAMILTONIAN (CPHF)
:ref:`apdx:CPHF` |w---w| Do explicit hamiltonian only?
* **Type**: :ref:`boolean `
* **Default**: false
FITTING_ALGORITHM (CPHF)
:ref:`apdx:CPHF` |w---w| Fitting algorithm (0 for old, 1 for new)
* **Type**: integer
* **Default**: 0
FITTING_CONDITION (CPHF)
:ref:`apdx:CPHF` |w---w| The maximum reciprocal condition allowed in the fitting metric
* **Type**: double
* **Default**: 1.0e-12
INDEPENDENT_J_TYPE (CPHF)
:ref:`apdx:CPHF` |w---w| JK Independent options
* **Type**: string
* **Possible Values**: DIRECT\_SCREENING
* **Default**: DIRECT\_SCREENING
MODULE (CPHF)
:ref:`apdx:CPHF` |w---w| What app to test?
* **Type**: string
* **Possible Values**: RCIS, RCPHF, RTDHF, RCPKS, RTDA, RTDDFT
* **Default**: RCIS
OMP_N_THREAD (CPHF)
:ref:`apdx:CPHF` |w---w| The maximum number of integral threads (0 for omp_get_max_threads())
* **Type**: integer
* **Default**: 0
PRINT (CPHF)
:ref:`apdx:CPHF` |w---w| The amount of information printed to the output file
* **Type**: integer
* **Default**: 1
SCF_TYPE (CPHF)
:ref:`apdx:CPHF` |w---w| SCF Type
* **Type**: string
* **Possible Values**: DIRECT, DF, PK, OUT\_OF\_CORE, PS, INDEPENDENT, GTFOCK
* **Default**: DIRECT
SCHWARZ_CUTOFF (CPHF)
:ref:`apdx:CPHF` |w---w| The schwarz cutoff value
* **Type**: double
* **Default**: 1.0e-12
SOLVER_CONVERGENCE (CPHF)
:ref:`apdx:CPHF` |w---w| Solver convergence threshold (max 2-norm).
* **Type**: :ref:`conv double `
* **Default**: 1.0e-6
SOLVER_EXACT_DIAGONAL (CPHF)
:ref:`apdx:CPHF` |w---w| Solver exact diagonal or eigenvalue difference?
* **Type**: :ref:`boolean `
* **Default**: false
SOLVER_MAXITER (CPHF)
:ref:`apdx:CPHF` |w---w| Solver maximum iterations
* **Type**: integer
* **Default**: 100
SOLVER_MAX_SUBSPACE (CPHF)
:ref:`apdx:CPHF` |w---w| DL Solver maximum number of subspace vectors
* **Type**: integer
* **Default**: 6
SOLVER_MIN_SUBSPACE (CPHF)
:ref:`apdx:CPHF` |w---w| DL Solver number of subspace vectors to collapse to
* **Type**: integer
* **Default**: 2
SOLVER_NORM (CPHF)
:ref:`apdx:CPHF` |w---w| DL Solver minimum corrector norm to add to subspace
* **Type**: double
* **Default**: 1.0e-6
SOLVER_N_GUESS (CPHF)
:ref:`apdx:CPHF` |w---w| DL Solver number of guesses
* **Type**: integer
* **Default**: 1
SOLVER_N_ROOT (CPHF)
:ref:`apdx:CPHF` |w---w| DL Solver number of roots
* **Type**: integer
* **Default**: 1
SOLVER_PRECONDITION (CPHF)
:ref:`apdx:CPHF` |w---w| Solver precondition type
* **Type**: string
* **Possible Values**: SUBSPACE, JACOBI, NONE
* **Default**: JACOBI
SOLVER_PRECONDITION_MAXITER (CPHF)
:ref:`apdx:CPHF` |w---w| Solver precondtion max steps
* **Type**: integer
* **Default**: 1
SOLVER_PRECONDITION_STEPS (CPHF)
:ref:`apdx:CPHF` |w---w| Solver precondition step type
* **Type**: string
* **Possible Values**: CONSTANT, TRIANGULAR
* **Default**: TRIANGULAR
SOLVER_QUANTITY (CPHF)
:ref:`apdx:CPHF` |w---w| Solver residue or eigenvector delta
* **Type**: string
* **Possible Values**: EIGENVECTOR, RESIDUAL
* **Default**: RESIDUAL
SOLVER_TYPE (CPHF)
:ref:`apdx:CPHF` |w---w| Solver type (for interchangeable solvers)
* **Type**: string
* **Possible Values**: DL, RAYLEIGH
* **Default**: DL
TDHF_MEM_SAFETY_FACTOR (CPHF)
:ref:`apdx:CPHF` |w---w| Memory safety factor for allocating JK
* **Type**: double
* **Default**: 0.75
ALGORITHM (DCFT)
:ref:`apdx:DCFT` |w---w| Algorithm to use for the density cumulant and orbital updates in the DCFT energy computation. Two-step algorithm is usually more efficient for small systems, but for large systems simultaneous algorithm (default) is recommended. If convergence problems are encountered (especially for highly symmetric systems) QC algorithm can be used.
* **Type**: string
* **Possible Values**: TWOSTEP, SIMULTANEOUS, QC
* **Default**: SIMULTANEOUS
AO_BASIS (DCFT)
:ref:`apdx:DCFT` |w---w| Controls whether to avoid the AO->MO transformation of the two-electron integrals for the four-virtual case () by computing the corresponding terms in the AO basis. AO_BASIS = DISK algorithm reduces the memory requirements and can significantly reduce the cost of the energy computation if SIMULTANEOUS algorithm is used. For the TWOSTEP algorithm, however, AO_BASIS = DISK option is not recommended due to extra I/O.
* **Type**: string
* **Possible Values**: NONE, DISK
* **Default**: DISK
DCFT_FUNCTIONAL (DCFT)
:ref:`apdx:DCFT` |w---w| Chooses appropriate DCFT method
* **Type**: string
* **Possible Values**: DC-06, DC-12, ODC-06, ODC-12, ODC-13, CEPA0
* **Default**: ODC-12
DCFT_TYPE (DCFT)
:ref:`apdx:DCFT` |w---w| What algorithm to use for the DCFT computation
* **Type**: string
* **Possible Values**: CONV, DF
* **Default**: CONV
DF_BASIS_DCFT (DCFT)
:ref:`apdx:DCFT` |w---w| Auxiliary basis set for DCFT density fitting computations. :ref:`Defaults ` to a RI basis.
* **Type**: string
* **Possible Values**: :ref:`basis string `
* **Default**: No Default
DIIS_START_CONVERGENCE (DCFT)
:ref:`apdx:DCFT` |w---w| Value of RMS of the density cumulant residual and SCF error vector below which DIIS extrapolation starts. Same keyword controls the DIIS extrapolation for the solution of the response equations.
* **Type**: :ref:`conv double `
* **Default**: 1e-3
E_CONVERGENCE (DCFT)
:ref:`apdx:DCFT` |w---w| Convergence criterion for energy. See Table :ref:`Post-SCF Convergence ` for default convergence criteria for different calculation types.
* **Type**: :ref:`conv double `
* **Default**: 1e-10
GUESS_R_CONVERGENCE (DCFT)
:ref:`apdx:DCFT` |w---w| Convergence criterion for the density cumulant and orbital guess for the variationally orbital-optimized DCFT methods. Currently only available for ALGORITHM = SIMULTANEOUS.
* **Type**: :ref:`conv double `
* **Default**: 1e-3
MAXITER (DCFT)
:ref:`apdx:DCFT` |w---w| Maximum number of macro- or micro-iterations for both energy and response equations
* **Type**: integer
* **Default**: 40
MOLDEN_WRITE (DCFT)
:ref:`apdx:DCFT` |w---w| Do write a MOLDEN output file? If so, the filename will end in .molden, and the prefix is determined by |globals__writer_file_label| (if set), or else by the name of the output file plus the name of the current molecule.
* **Type**: :ref:`boolean `
* **Default**: false
ODC_GUESS (DCFT)
:ref:`apdx:DCFT` |w---w| Whether to perform a guess DC-06 or DC-12 computation for ODC-06 or ODC-12 methods, respectively. Currently only available for ALGORITHM = SIMULTANEOUS.
* **Type**: :ref:`boolean `
* **Default**: false
QC_COUPLING (DCFT)
:ref:`apdx:DCFT` |w---w| Controls whether to include the coupling terms in the DCFT electronic Hessian (for ALOGRITHM = QC with QC_TYPE = SIMULTANEOUS only)
* **Type**: :ref:`boolean `
* **Default**: false
QC_TYPE (DCFT)
:ref:`apdx:DCFT` |w---w| Controls the type of the quadratically-convergent algorithm (effective for ALGORITHM = QC). If set to TWOSTEP the Newton-Raphson equations are only solved for the orbital updates, the cumulant is updated using the standard Jacobi algorithm. If set to SIMULTANEOUS both cumulant and orbitals are updated in a single Newton-Raphson step.
* **Type**: string
* **Possible Values**: TWOSTEP, SIMULTANEOUS
* **Default**: SIMULTANEOUS
REFERENCE (DCFT)
:ref:`apdx:DCFT` |w---w| Reference wavefunction type
* **Type**: string
* **Possible Values**: UHF, RHF, ROHF
* **Default**: RHF
RESPONSE_ALGORITHM (DCFT)
:ref:`apdx:DCFT` |w---w| Algorithm to use for the solution of DC-06 response equations in computation of analytic gradients and properties
* **Type**: string
* **Possible Values**: TWOSTEP, SIMULTANEOUS
* **Default**: TWOSTEP
R_CONVERGENCE (DCFT)
:ref:`apdx:DCFT` |w---w| Convergence criterion for the RMS of the residual vector in density cumulant updates, as well as the solution of the density cumulant and orbital response equations. In the orbital updates controls the RMS of the SCF error vector
* **Type**: :ref:`conv double `
* **Default**: 1e-10
THREE_PARTICLE (DCFT)
:ref:`apdx:DCFT` |w---w| Whether to compute three-particle energy correction or not
* **Type**: string
* **Possible Values**: NONE, PERTURBATIVE
* **Default**: NONE
AVG_STATES (DETCI)
:ref:`apdx:DETCI` |w---w| Array giving the root numbers of the states to average in a state-averaged procedure such as SA-CASSCF. Root numbering starts from 1.
* **Type**: array
* **Default**: No Default
AVG_WEIGHTS (DETCI)
:ref:`apdx:DETCI` |w---w| Array giving the weights for each state in a state-averaged procedure
* **Type**: array
* **Default**: No Default
A_RAS3_MAX (DETCI)
:ref:`apdx:DETCI` |w---w| maximum number of alpha electrons in RAS III
* **Type**: integer
* **Default**: -1
B_RAS3_MAX (DETCI)
:ref:`apdx:DETCI` |w---w| maximum number of beta electrons in RAS III
* **Type**: integer
* **Default**: -1
CALC_S_SQUARED (DETCI)
:ref:`apdx:DETCI` |w---w| Do calculate the value of :math:`\langle S^2\rangle` for each root? Only supported for |detci__icore| = 1.
* **Type**: :ref:`boolean `
* **Default**: false
CIBLKS_PRINT (DETCI)
:ref:`apdx:DETCI` |w---w| Do print a summary of the CI blocks?
* **Type**: :ref:`boolean `
* **Default**: false
CI_MAXITER (DETCI)
:ref:`apdx:DETCI` |w---w| Maximum number of iterations to diagonalize the Hamiltonian
* **Type**: integer
* **Default**: 24
CI_NUM_THREADS (DETCI)
:ref:`apdx:DETCI` |w---w| Number of threads for DETCI.
* **Type**: integer
* **Default**: 1
DETCI_FREEZE_CORE (DETCI)
:ref:`apdx:DETCI` |w---w| Do freeze core orbitals?
* **Type**: :ref:`boolean `
* **Default**: true
EX_LEVEL (DETCI)
:ref:`apdx:DETCI` |w---w| The CI excitation level
* **Type**: integer
* **Default**: 2
E_CONVERGENCE (DETCI)
:ref:`apdx:DETCI` |w---w| Convergence criterion for energy. See Table :ref:`Post-SCF Convergence ` for default convergence criteria for different calculation types.
* **Type**: :ref:`conv double `
* **Default**: 1e-6
FCI (DETCI)
:ref:`apdx:DETCI` |w---w| Do a full CI (FCI)? If TRUE, overrides the value of |detci__ex_level|.
* **Type**: :ref:`boolean `
* **Default**: false
ICORE (DETCI)
:ref:`apdx:DETCI` |w---w| Specifies how to handle buffering of CI vectors. A value of 0 makes the program perform I/O one RAS subblock at a time; 1 uses entire CI vectors at a time; and 2 uses one irrep block at a time. Values of 0 or 2 cause some inefficiency in the I/O (requiring multiple reads of the C vector when constructing H in the iterative subspace if |detci__diag_method| = SEM), but require less core memory.
* **Type**: integer
* **Default**: 1
ISTOP (DETCI)
:ref:`apdx:DETCI` |w---w| Do stop DETCI after string information is formed and before integrals are read?
* **Type**: :ref:`boolean `
* **Default**: false
MS0 (DETCI)
:ref:`apdx:DETCI` |w---w| Do use the :math:`M_s = 0` component of the state? Defaults to TRUE if closed-shell and FALSE otherwise. Related to the |detci__s| option.
* **Type**: :ref:`boolean `
* **Default**: false
NUM_DETS_PRINT (DETCI)
:ref:`apdx:DETCI` |w---w| Number of important determinants to print
* **Type**: integer
* **Default**: 20
NUM_ROOTS (DETCI)
:ref:`apdx:DETCI` |w---w| number of CI roots to find
* **Type**: integer
* **Default**: 1
RAS34_MAX (DETCI)
:ref:`apdx:DETCI` |w---w| maximum number of electrons in RAS III + IV
* **Type**: integer
* **Default**: -1
RAS3_MAX (DETCI)
:ref:`apdx:DETCI` |w---w| maximum number of electrons in RAS III
* **Type**: integer
* **Default**: -1
RAS4_MAX (DETCI)
:ref:`apdx:DETCI` |w---w| maximum number of electrons in RAS IV
* **Type**: integer
* **Default**: -1
REFERENCE (DETCI)
:ref:`apdx:DETCI` |w---w| Reference wavefunction type
* **Type**: string
* **Possible Values**: RHF, ROHF
* **Default**: RHF
R_CONVERGENCE (DETCI)
:ref:`apdx:DETCI` |w---w| Convergence criterion for CI residual vector in the Davidson algorithm (RMS error). The default is 1e-4 for energies and 1e-7 for gradients.
* **Type**: :ref:`conv double `
* **Default**: 1e-4
S (DETCI)
:ref:`apdx:DETCI` |w---w| The value of the spin quantum number :math:`S` is given by this option. The default is determined by the value of the multiplicity. This is used for two things: (1) determining the phase of the redundant half of the CI vector when the :math:`M_s = 0` component is used (i.e., |detci__ms0| = ``TRUE``), and (2) making sure the guess vector has the desired value of :math:`\langle S^2\rangle` (if |detci__calc_s_squared| is ``TRUE`` and |detci__icore| = ``1``).
* **Type**: double
* **Default**: 0.0
VAL_EX_LEVEL (DETCI)
:ref:`apdx:DETCI` |w---w| In a RAS CI, this is the additional excitation level for allowing electrons out of RAS I into RAS II. The maximum number of holes in RAS I is therefore |detci__ex_level| + VAL_EX_LEVEL.
* **Type**: integer
* **Default**: 0
DIAG_METHOD (DETCI)
:ref:`apdx:DETCI` |w---w| This specifies which method is to be used in diagonalizing the Hamiltonian. The valid options are: ``RSP``, to form the entire H matrix and diagonalize using libciomr to obtain all eigenvalues (n.b. requires HUGE memory); ``OLSEN``, to use Olsen's preconditioned inverse subspace method (1990); ``MITRUSHENKOV``, to use a 2x2 Olsen/Davidson method; and ``DAVIDSON`` (or ``SEM``) to use Liu's Simultaneous Expansion Method, which is identical to the Davidson method if only one root is to be found. There also exists a SEM debugging mode, ``SEMTEST``. The ``SEM`` method is the most robust, but it also requires :math:`2NM+1` CI vectors on disk, where :math:`N` is the maximum number of iterations and :math:`M` is the number of roots.
* **Type**: string
* **Possible Values**: RSP, OLSEN, MITRUSHENKOV, DAVIDSON, SEM, SEMTEST
* **Default**: SEM
LSE (DETCI)
:ref:`apdx:DETCI` |w---w| Do use least-squares extrapolation in iterative solution of CI vector?
* **Type**: :ref:`boolean `
* **Default**: false
LSE_COLLAPSE (DETCI)
:ref:`apdx:DETCI` |w---w| Number of iterations between least-squares extrapolations
* **Type**: integer
* **Default**: 3
LSE_TOLERANCE (DETCI)
:ref:`apdx:DETCI` |w---w| Minimum converged energy for least-squares extrapolation to be performed
* **Type**: :ref:`conv double `
* **Default**: 3
PRECONDITIONER (DETCI)
:ref:`apdx:DETCI` |w---w| This specifies the type of preconditioner to use in the selected diagonalization method. The valid options are: ``DAVIDSON`` which approximates the Hamiltonian matrix by the diagonal elements; ``H0BLOCK_INV`` which uses an exact Hamiltonian of |detci__h0_blocksize| and explicitly inverts it; ``GEN_DAVIDSON`` which does a spectral decomposition of H0BLOCK; ``ITER_INV`` using an iterative approach to obtain the correction vector of H0BLOCK. The ``H0BLOCK_INV``, ``GEN_DAVIDSON``, and ``ITER_INV`` approaches are all formally equivalent but the ``ITER_INV`` is less computationally expensive. Default is ``DAVIDSON``.
* **Type**: string
* **Possible Values**: LANCZOS, DAVIDSON, GEN\_DAVIDSON, H0BLOCK, H0BLOCK\_INV, ITER\_INV, H0BLOCK\_COUPLING, EVANGELISTI
* **Default**: DAVIDSON
UPDATE (DETCI)
:ref:`apdx:DETCI` |w---w| The update or correction vector formula, either ``DAVIDSON`` (default) or ``OLSEN``.
* **Type**: string
* **Possible Values**: DAVIDSON, OLSEN
* **Default**: DAVIDSON
DIPMOM (DETCI)
:ref:`apdx:DETCI` |w---w| Do compute the dipole moment?
* **Type**: :ref:`boolean `
* **Default**: false
NAT_ORBS (DETCI)
:ref:`apdx:DETCI` |w---w| Build natural orbitals? The orbtials will be reordered by occuption number.
* **Type**: :ref:`boolean `
* **Default**: false
OPDM (DETCI)
:ref:`apdx:DETCI` |w---w| Do compute one-particle density matrix if not otherwise required?
* **Type**: :ref:`boolean `
* **Default**: false
OPDM_AVG (DETCI)
:ref:`apdx:DETCI` |w---w| Do average the OPDM over several roots in order to obtain a state-average one-particle density matrix? This density matrix can be diagonalized to obtain the CI natural orbitals.
* **Type**: :ref:`boolean `
* **Default**: false
OPDM_PRINT (DETCI)
:ref:`apdx:DETCI` |w---w| Do print the one-particle density matrix for each root?
* **Type**: :ref:`boolean `
* **Default**: false
TDM (DETCI)
:ref:`apdx:DETCI` |w---w| Do compute the transition density? Note: only transition densities between roots of the same symmetry will be evaluated. DETCI does not compute states of different irreps within the same computation; to do this, lower the symmetry of the computation.
* **Type**: :ref:`boolean `
* **Default**: false
TDM_PRINT (DETCI)
:ref:`apdx:DETCI` |w---w| Do print the transition density?
* **Type**: :ref:`boolean `
* **Default**: false
TDM_WRITE (DETCI)
:ref:`apdx:DETCI` |w---w| Do write the transition density?
* **Type**: :ref:`boolean `
* **Default**: false
TPDM_PRINT (DETCI)
:ref:`apdx:DETCI` |w---w| Do print the two-particle density matrix? (Warning: large tensor)
* **Type**: :ref:`boolean `
* **Default**: false
FOLLOW_ROOT (DETCI)
:ref:`apdx:DETCI` |w---w| The root to write out the two-particle density matrix for (the one-particle density matrices are written for all roots). Useful for a state-specific CASSCF or CI optimization on an excited state.
* **Type**: integer
* **Default**: 1
RESTART (DETCI)
:ref:`apdx:DETCI` |w---w| Do restart a DETCI iteration that terminated prematurely? It assumes that the CI and sigma vectors are on disk.
* **Type**: :ref:`boolean `
* **Default**: false
COLLAPSE_SIZE (DETCI)
:ref:`apdx:DETCI` |w---w| Gives the number of vectors to retain when the Davidson subspace is collapsed (see |detci__max_num_vecs|). If greater than one, the collapsed subspace retains the best estimate of the CI vector for the previous n iterations. Defaults to 1.
* **Type**: integer
* **Default**: 1
MAX_NUM_VECS (DETCI)
:ref:`apdx:DETCI` |w---w| Maximum number of Davidson subspace vectors which can be held on disk for the CI coefficient and sigma vectors. (There is one H(diag) vector and the number of D vectors is equal to the number of roots). When the number of vectors on disk reaches the value of MAX_NUM_VECS, the Davidson subspace will be collapsed to |detci__collapse_size| vectors for each root. This is very helpful for saving disk space. Defaults to |detci__ci_maxiter| * |detci__num_roots| + |detci__num_init_vecs|.
* **Type**: integer
* **Default**: 0
MPN (DETCI)
:ref:`apdx:DETCI` |w---w| Do compute the MPn series out to kth order where k is determined by |detci__max_num_vecs| ? For open-shell systems (|detci__reference| is ROHF, |detci__wfn| is ZAPTN), DETCI will compute the ZAPTn series. |detci__guess_vector| must be set to UNIT, |detci__hd_otf| must be set to TRUE, and |detci__hd_avg| must be set to orb_ener; these should happen by default for MPN = TRUE.
* **Type**: :ref:`boolean `
* **Default**: false
CC (DETCI)
:ref:`apdx:DETCI` |w---w| Do coupled-cluster computation?
* **Type**: :ref:`boolean `
* **Default**: false
CC_A_RAS3_MAX (DETCI)
:ref:`apdx:DETCI` |w---w| maximum number of alpha electrons in RAS III, for CC
* **Type**: integer
* **Default**: -1
CC_B_RAS3_MAX (DETCI)
:ref:`apdx:DETCI` |w---w| maximum number of beta electrons in RAS III, for CC
* **Type**: integer
* **Default**: -1
CC_EX_LEVEL (DETCI)
:ref:`apdx:DETCI` |w---w| The CC excitation level
* **Type**: integer
* **Default**: 2
CC_RAS34_MAX (DETCI)
:ref:`apdx:DETCI` |w---w| maximum number of electrons in RAS III + IV, for CC
* **Type**: integer
* **Default**: -1
CC_RAS3_MAX (DETCI)
:ref:`apdx:DETCI` |w---w| maximum number of electrons in RAS III, for CC
* **Type**: integer
* **Default**: -1
CC_RAS4_MAX (DETCI)
:ref:`apdx:DETCI` |w---w| maximum number of electrons in RAS IV, for CC
* **Type**: integer
* **Default**: -1
CC_VAL_EX_LEVEL (DETCI)
:ref:`apdx:DETCI` |w---w| The CC valence excitation level
* **Type**: integer
* **Default**: 0
CC_VECS_READ (DETCI)
:ref:`apdx:DETCI` |w---w| Do import a CC vector from disk?
* **Type**: :ref:`boolean `
* **Default**: false
CC_VECS_WRITE (DETCI)
:ref:`apdx:DETCI` |w---w| Do export a CC vector to disk?
* **Type**: :ref:`boolean `
* **Default**: false
DIIS (DETCI)
:ref:`apdx:DETCI` |w---w| Do use DIIS extrapolation to accelerate CC convergence?
* **Type**: :ref:`boolean `
* **Default**: true
DIIS_FREQ (DETCI)
:ref:`apdx:DETCI` |w---w| How often to do a DIIS extrapolation. 1 means do DIIS every iteration, 2 is every other iteration, etc.
* **Type**: integer
* **Default**: 1
DIIS_MAX_VECS (DETCI)
:ref:`apdx:DETCI` |w---w| Maximum number of error vectors stored for DIIS extrapolation
* **Type**: integer
* **Default**: 5
DIIS_MIN_VECS (DETCI)
:ref:`apdx:DETCI` |w---w| Minimum number of error vectors stored for DIIS extrapolation
* **Type**: integer
* **Default**: 2
DIIS_START_ITER (DETCI)
:ref:`apdx:DETCI` |w---w| Iteration at which to start using DIIS
* **Type**: integer
* **Default**: 1
NUM_AMPS_PRINT (DETCI)
:ref:`apdx:DETCI` |w---w| Number of important CC amplitudes per excitation level to print. CC analog to |detci__num_dets_print|.
* **Type**: integer
* **Default**: 10
DF_BASIS_MCSCF (DETCI)
:ref:`apdx:DETCI` |w---w| Auxiliary basis set for MCSCF density fitted ERI computations. This only effects the "Q" matrix in Helgaker's language. :ref:`Defaults ` to a JKFIT basis.
* **Type**: string
* **Possible Values**: :ref:`basis string `
* **Default**: No Default
MCSCF_DIIS_FREQ (DETCI)
:ref:`apdx:DETCI` |w---w| How often to do a DIIS extrapolation
* **Type**: integer
* **Default**: 1
MCSCF_DIIS_MAX_VECS (DETCI)
:ref:`apdx:DETCI` |w---w| Maximum number of DIIS vectors
* **Type**: integer
* **Default**: 8
MCSCF_DIIS_START (DETCI)
:ref:`apdx:DETCI` |w---w| Iteration to turn on DIIS
* **Type**: integer
* **Default**: 3
MCSCF_E_CONVERGENCE (DETCI)
:ref:`apdx:DETCI` |w---w| Convergence criterion for energy. See Table :ref:`Post-SCF Convergence ` for default convergence criteria for different calculation types.
* **Type**: :ref:`conv double `
* **Default**: 1e-7
MCSCF_MAXITER (DETCI)
:ref:`apdx:DETCI` |w---w| Maximum number MCSCF of iterations
* **Type**: integer
* **Default**: 30
MCSCF_MAX_ROT (DETCI)
:ref:`apdx:DETCI` |w---w| Maximum value in the rotation matrix. If a value is greater than this number all values are scaled.
* **Type**: double
* **Default**: 0.5
MCSCF_R_CONVERGENCE (DETCI)
:ref:`apdx:DETCI` |w---w| Convergence criterion for the RMS of the orbital gradient
* **Type**: :ref:`conv double `
* **Default**: 1e-4
BASIS (DFMP2)
:ref:`apdx:DFMP2` |w---w| Primary basis set
* **Type**: string
* **Possible Values**: :ref:`basis string `
* **Default**: NONE
DFMP2_MEM_FACTOR (DFMP2)
:ref:`apdx:DFMP2` |w---w| \% of memory for DF-MP2 three-index buffers
* **Type**: double
* **Default**: 0.9
DFMP2_P2_TOLERANCE (DFMP2)
:ref:`apdx:DFMP2` |w---w| Minimum error in the 2-norm of the P(2) matrix for corrections to Lia and P.
* **Type**: :ref:`conv double `
* **Default**: 0.0
DFMP2_P_TOLERANCE (DFMP2)
:ref:`apdx:DFMP2` |w---w| Minimum error in the 2-norm of the P matrix for skeleton-core Fock matrix derivatives.
* **Type**: :ref:`conv double `
* **Default**: 0.0
DF_BASIS_MP2 (DFMP2)
:ref:`apdx:DFMP2` |w---w| Auxiliary basis set for MP2 density fitting computations. :ref:`Defaults ` to a RI basis.
* **Type**: string
* **Possible Values**: :ref:`basis string `
* **Default**: No Default
DF_INTS_NUM_THREADS (DFMP2)
:ref:`apdx:DFMP2` |w---w| Number of threads to compute integrals with. 0 is wild card
* **Type**: integer
* **Default**: 0
INTS_TOLERANCE (DFMP2)
:ref:`apdx:DFMP2` |w---w| Minimum absolute value below which integrals are neglected.
* **Type**: :ref:`conv double `
* **Default**: 0.0
MP2_OS_SCALE (DFMP2)
:ref:`apdx:DFMP2` |w---w| OS Scale
* **Type**: double
* **Default**: 6.0/5.0
MP2_SS_SCALE (DFMP2)
:ref:`apdx:DFMP2` |w---w| SS Scale
* **Type**: double
* **Default**: 1.0/3.0
ONEPDM (DFMP2)
:ref:`apdx:DFMP2` |w---w| Do compute one-particle density matrix?
* **Type**: :ref:`boolean `
* **Default**: false
OPDM_RELAX (DFMP2)
:ref:`apdx:DFMP2` |w---w| Do relax the one-particle density matrix?
* **Type**: :ref:`boolean `
* **Default**: true
CC_DIIS_MAX_VECS (DFOCC)
:ref:`apdx:DFOCC` |w---w| Maximum number of vectors used in amplitude DIIS
* **Type**: integer
* **Default**: 6
CC_DIIS_MIN_VECS (DFOCC)
:ref:`apdx:DFOCC` |w---w| Minimum number of vectors used in amplitude DIIS
* **Type**: integer
* **Default**: 2
CC_LAMBDA (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do solve lambda amplitute equations?
* **Type**: :ref:`boolean `
* **Default**: false
CC_MAXITER (DFOCC)
:ref:`apdx:DFOCC` |w---w| Maximum number of iterations to determine the amplitudes
* **Type**: integer
* **Default**: 50
CHOLESKY (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do Cholesky decomposition of the ERI tensor
* **Type**: :ref:`boolean `
* **Default**: false
CHOLESKY_TOLERANCE (DFOCC)
:ref:`apdx:DFOCC` |w---w| tolerance for Cholesky decomposition of the ERI tensor
* **Type**: :ref:`conv double `
* **Default**: 1.0e-4
COMPUT_S2 (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do compute for DF-OMP2/DF-MP2?
* **Type**: :ref:`boolean `
* **Default**: false
CUTOFF (DFOCC)
:ref:`apdx:DFOCC` |w---w| Cutoff value for numerical procedures
* **Type**: integer
* **Default**: 8
DO_DIIS (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do apply DIIS extrapolation?
* **Type**: :ref:`boolean `
* **Default**: true
DO_LEVEL_SHIFT (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do apply level shifting?
* **Type**: :ref:`boolean `
* **Default**: true
DO_SCS (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do perform spin-component-scaled OMP2 (SCS-OMP2)? In all computation, SCS-OMP2 energy is computed automatically. However, in order to perform geometry optimizations and frequency computations with SCS-OMP2, one needs to set 'DO_SCS' to true
* **Type**: :ref:`boolean `
* **Default**: false
DO_SOS (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do perform spin-opposite-scaled OMP2 (SOS-OMP2)? In all computation, SOS-OMP2 energy is computed automatically. However, in order to perform geometry optimizations and frequency computations with SOS-OMP2, one needs to set 'DO_SOS' to true
* **Type**: :ref:`boolean `
* **Default**: false
E3_SCALE (DFOCC)
:ref:`apdx:DFOCC` |w---w| CEPA opposite-spin scaling value from SCS-CCSD
* **Type**: double
* **Default**: 0.25
EKT_IP (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do compute ionization potentials based on the extended Koopmans' theorem?
* **Type**: :ref:`boolean `
* **Default**: false
E_CONVERGENCE (DFOCC)
:ref:`apdx:DFOCC` |w---w| Convergence criterion for energy. See Table :ref:`Post-SCF Convergence ` for default convergence criteria for different calculation types.
* **Type**: :ref:`conv double `
* **Default**: 1e-6
HESS_TYPE (DFOCC)
:ref:`apdx:DFOCC` |w---w| Type of the MO Hessian matrix
* **Type**: string
* **Possible Values**: APPROX\_DIAG, APPROX\_DIAG\_EKT, APPROX\_DIAG\_HF, HF
* **Default**: HF
INTEGRAL_CUTOFF (DFOCC)
:ref:`apdx:DFOCC` |w---w| Cutoff value for DF integrals
* **Type**: integer
* **Default**: 9
LEVEL_SHIFT (DFOCC)
:ref:`apdx:DFOCC` |w---w| Level shift to aid convergence
* **Type**: double
* **Default**: 0.02
LINEQ_SOLVER (DFOCC)
:ref:`apdx:DFOCC` |w---w| The solver will be used for simultaneous linear equations.
* **Type**: string
* **Possible Values**: CDGESV, FLIN, POPLE
* **Default**: CDGESV
MAX_MOGRAD_CONVERGENCE (DFOCC)
:ref:`apdx:DFOCC` |w---w| Convergence criterion for maximum orbital gradient
* **Type**: :ref:`conv double `
* **Default**: 1e-3
MOLDEN_WRITE (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do write a MOLDEN output file? If so, the filename will end in .molden, and the prefix is determined by |globals__writer_file_label| (if set), or else by the name of the output file plus the name of the current molecule.
* **Type**: :ref:`boolean `
* **Default**: false
MO_DIIS_NUM_VECS (DFOCC)
:ref:`apdx:DFOCC` |w---w| Number of vectors used in orbital DIIS
* **Type**: integer
* **Default**: 6
MO_MAXITER (DFOCC)
:ref:`apdx:DFOCC` |w---w| Maximum number of iterations to determine the orbitals
* **Type**: integer
* **Default**: 50
MO_STEP_MAX (DFOCC)
:ref:`apdx:DFOCC` |w---w| Maximum step size in orbital-optimization procedure
* **Type**: double
* **Default**: 0.5
MP2_AMP_TYPE (DFOCC)
:ref:`apdx:DFOCC` |w---w| The algorithm that used to handle mp2 amplitudes. The DIRECT option means compute amplitudes on the fly whenever they are necessary.
* **Type**: string
* **Possible Values**: DIRECT, CONV
* **Default**: DIRECT
MP2_OS_SCALE (DFOCC)
:ref:`apdx:DFOCC` |w---w| MP2 opposite-spin scaling value
* **Type**: double
* **Default**: 6.0/5.0
MP2_SOS_SCALE (DFOCC)
:ref:`apdx:DFOCC` |w---w| MP2 Spin-opposite scaling (SOS) value
* **Type**: double
* **Default**: 1.3
MP2_SOS_SCALE2 (DFOCC)
:ref:`apdx:DFOCC` |w---w| Spin-opposite scaling (SOS) value for optimized-MP2 orbitals
* **Type**: double
* **Default**: 1.2
MP2_SS_SCALE (DFOCC)
:ref:`apdx:DFOCC` |w---w| MP2 same-spin scaling value
* **Type**: double
* **Default**: 1.0/3.0
NAT_ORBS (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do compute natural orbitals?
* **Type**: :ref:`boolean `
* **Default**: false
OCC_ORBS_PRINT (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do print OCC orbital energies?
* **Type**: :ref:`boolean `
* **Default**: false
OEPROP (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do compute one electron properties?
* **Type**: :ref:`boolean `
* **Default**: false
OO_SCALE (DFOCC)
:ref:`apdx:DFOCC` |w---w| OO scaling factor used in MSD
* **Type**: double
* **Default**: 0.01
OPT_METHOD (DFOCC)
:ref:`apdx:DFOCC` |w---w| The orbital optimization algorithm. Presently Quasy Newton-Raphson algorithm avaliable with several Hessian options.
* **Type**: string
* **Possible Values**: QNR
* **Default**: QNR
ORB_OPT (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do optimize the orbitals?
* **Type**: :ref:`boolean `
* **Default**: true
ORB_RESP_SOLVER (DFOCC)
:ref:`apdx:DFOCC` |w---w| The algorithm will be used for solving the orbital-response equations. The LINEQ option create the MO Hessian and solve the simultaneous linear equations with method choosen by the LINEQ_SOLVER option. The PCG option does not create the MO Hessian explicitly, instead it solves the simultaneous equations iteratively with the preconditioned conjugate gradient method.
* **Type**: string
* **Possible Values**: PCG, LINEQ
* **Default**: PCG
ORTH_TYPE (DFOCC)
:ref:`apdx:DFOCC` |w---w| The algorithm for orthogonalization of MOs
* **Type**: string
* **Possible Values**: GS, MGS
* **Default**: MGS
PCG_BETA_TYPE (DFOCC)
:ref:`apdx:DFOCC` |w---w| CEPA type such as CEPA0, CEPA1 etc. currently we have only CEPA0.
* **Type**: string
* **Possible Values**: FLETCHER\_REEVES, POLAK\_RIBIERE
* **Default**: FLETCHER\_REEVES
PCG_CONVERGENCE (DFOCC)
:ref:`apdx:DFOCC` |w---w| Convergence criterion for residual vector of preconditioned conjugate gradient method.
* **Type**: :ref:`conv double `
* **Default**: 1e-6
PCG_MAXITER (DFOCC)
:ref:`apdx:DFOCC` |w---w| Maximum number of preconditioned conjugate gradient iterations.
* **Type**: integer
* **Default**: 50
PPL_TYPE (DFOCC)
:ref:`apdx:DFOCC` |w---w| Type of the CCSD PPL term.
* **Type**: string
* **Possible Values**: LOW\_MEM, HIGH\_MEM, CD, AUTO
* **Default**: AUTO
QCHF (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do perform a QCHF computation?
* **Type**: :ref:`boolean `
* **Default**: false
READ_SCF_3INDEX (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do read 3-index integrals from SCF files?
* **Type**: :ref:`boolean `
* **Default**: true
REGULARIZATION (DFOCC)
:ref:`apdx:DFOCC` |w---w| Do use regularized denominators?
* **Type**: :ref:`boolean `
* **Default**: false
REG_PARAM (DFOCC)
:ref:`apdx:DFOCC` |w---w| Regularization parameter
* **Type**: double
* **Default**: 0.4
RMS_MOGRAD_CONVERGENCE (DFOCC)
:ref:`apdx:DFOCC` |w---w| Convergence criterion for RMS orbital gradient. Default adjusts depending on |occ__e_convergence|.
* **Type**: :ref:`conv double `
* **Default**: 1e-6
R_CONVERGENCE (DFOCC)
:ref:`apdx:DFOCC` |w---w| Convergence criterion for amplitudes (residuals).
* **Type**: :ref:`conv double `
* **Default**: 1e-5
SCS_TYPE (DFOCC)
:ref:`apdx:DFOCC` |w---w| Type of the SCS method
* **Type**: string
* **Possible Values**: SCS, SCSN, SCSVDW, SCSMI
* **Default**: SCS
SOS_TYPE (DFOCC)
:ref:`apdx:DFOCC` |w---w| Type of the SOS method
* **Type**: string
* **Possible Values**: SOS, SOSPI
* **Default**: SOS
TRIPLES_IABC_TYPE (DFOCC)
:ref:`apdx:DFOCC` |w---w| The algorithm to handle (ia|bc) type integrals that used for (T) correction.
* **Type**: string
* **Possible Values**: INCORE, AUTO, DIRECT, DISK
* **Default**: DISK
WFN_TYPE (DFOCC)
:ref:`apdx:DFOCC` |w---w| Type of the wavefunction.
* **Type**: string
* **Possible Values**: DF-OMP2, DF-OMP3, DF-OLCCD, DF-OMP2.5, DFGRAD, DF-CCSD, DF-CCD, DF-CCSD(T), DF-CCSD(AT), QCHF
* **Default**: DF-OMP2
DMRG_CASPT2_CALC (DMRG)
:ref:`apdx:DMRG` |w---w| Do calculate the DMRG-CASPT2 energy after the DMRGSCF calculations are done?
* **Type**: :ref:`boolean `
* **Default**: false
DMRG_CASPT2_IMAG (DMRG)
:ref:`apdx:DMRG` |w---w| CASPT2 Imaginary shift
* **Type**: double
* **Default**: 0.0
DMRG_CASPT2_IPEA (DMRG)
:ref:`apdx:DMRG` |w---w| CASPT2 IPEA shift
* **Type**: double
* **Default**: 0.0
DMRG_CASPT2_ORBS (DMRG)
:ref:`apdx:DMRG` |w---w| Whether to calculate the DMRG-CASPT2 energy after the DMRGSCF calculations are done.
* **Type**: string
* **Possible Values**: PSEUDOCANONICAL, ACTIVE
* **Default**: PSEUDOCANONICAL
DMRG_DIIS (DMRG)
:ref:`apdx:DMRG` |w---w| Whether or not to use DIIS for DMRG.
* **Type**: :ref:`boolean `
* **Default**: false
DMRG_DIIS_WRITE (DMRG)
:ref:`apdx:DMRG` |w---w| Whether or not to store the DIIS checkpoint on disk (convenient for restarting).
* **Type**: :ref:`boolean `
* **Default**: true
DMRG_EXCITATION (DMRG)
:ref:`apdx:DMRG` |w---w| Which root is targeted: 0 means ground state, 1 first excited state, etc.
* **Type**: integer
* **Default**: 0
DMRG_IRREP (DMRG)
:ref:`apdx:DMRG` |w---w| The DMRG wavefunction irrep uses the same conventions as PSI4. How convenient :-). Just to avoid confusion, it's copied here. It can also be found on http://sebwouters.github.io/CheMPS2/doxygen/classCheMPS2_1_1Irreps.html . Symmetry Conventions Irrep Number & Name Group Number & Name 0 1 2 3 4 5 6 7 0: c1 A 1: ci Ag Au 2: c2 A B 3: cs A' A'' 4: d2 A B1 B2 B3 5: c2v A1 A2 B1 B2 6: c2h Ag Bg Au Bu 7: d2h Ag B1g B2g B3g Au B1u B2u B3u
* **Type**: integer
* **Default**: -1
DMRG_LOCAL_INIT (DMRG)
:ref:`apdx:DMRG` |w---w| Whether to start the active space localization process from a random unitary or the unit matrix.
* **Type**: :ref:`boolean `
* **Default**: true
DMRG_MOLDEN_WRITE (DMRG)
:ref:`apdx:DMRG` |w---w| DMRG-CI or converged DMRG-SCF orbitals in molden format
* **Type**: :ref:`boolean `
* **Default**: false
DMRG_MPS_WRITE (DMRG)
:ref:`apdx:DMRG` |w---w| Whether or not to create intermediary MPS checkpoints
* **Type**: :ref:`boolean `
* **Default**: false
DMRG_MULTIPLICITY (DMRG)
:ref:`apdx:DMRG` |w---w| The DMRG wavefunction multiplicity in the form (2S+1)
* **Type**: integer
* **Default**: -1
DMRG_OPDM_AO_PRINT (DMRG)
:ref:`apdx:DMRG` |w---w| Print out the density matrix in the AO basis
* **Type**: :ref:`boolean `
* **Default**: false
DMRG_PRINT_CORR (DMRG)
:ref:`apdx:DMRG` |w---w| Whether or not to print the correlation functions after the DMRG calculation
* **Type**: :ref:`boolean `
* **Default**: false
DMRG_SCF_ACTIVE_SPACE (DMRG)
:ref:`apdx:DMRG` |w---w| Which active space to use for DMRG calculations: --> input with SCF rotations (INPUT); --> natural orbitals (NO); --> localized and ordered orbitals (LOC)
* **Type**: string
* **Possible Values**: INPUT, NO, LOC
* **Default**: INPUT
DMRG_SCF_DIIS_THR (DMRG)
:ref:`apdx:DMRG` |w---w| When the update norm is smaller than this value DIIS starts.
* **Type**: double
* **Default**: 1e-2
DMRG_SCF_GRAD_THR (DMRG)
:ref:`apdx:DMRG` |w---w| The density RMS convergence to stop an instruction during successive DMRG instructions
* **Type**: double
* **Default**: 1.e-6
DMRG_SCF_MAX_ITER (DMRG)
:ref:`apdx:DMRG` |w---w| Maximum number of DMRG iterations
* **Type**: integer
* **Default**: 100
DMRG_SCF_STATE_AVG (DMRG)
:ref:`apdx:DMRG` |w---w| Whether or not to use state-averaging for roots >=2 with DMRG-SCF.
* **Type**: :ref:`boolean `
* **Default**: true
DMRG_SWEEP_DVDSON_RTOL (DMRG)
:ref:`apdx:DMRG` |w---w| The residual tolerances for the Davidson diagonalization during DMRG instructions
* **Type**: array
* **Default**: No Default
DMRG_SWEEP_ENERGY_CONV (DMRG)
:ref:`apdx:DMRG` |w---w| The energy convergence to stop an instruction during successive DMRG instructions
* **Type**: array
* **Default**: No Default
DMRG_SWEEP_MAX_SWEEPS (DMRG)
:ref:`apdx:DMRG` |w---w| The maximum number of sweeps to stop an instruction during successive DMRG instructions
* **Type**: array
* **Default**: No Default
DMRG_SWEEP_NOISE_PREFAC (DMRG)
:ref:`apdx:DMRG` |w---w| The noiseprefactors for successive DMRG instructions
* **Type**: array
* **Default**: No Default
DMRG_SWEEP_STATES (DMRG)
:ref:`apdx:DMRG` |w---w| The number of reduced renormalized basis states to be retained during successive DMRG instructions
* **Type**: array
* **Default**: No Default
DMRG_UNITARY_WRITE (DMRG)
:ref:`apdx:DMRG` |w---w| Whether or not to store the unitary on disk (convenient for restarting).
* **Type**: :ref:`boolean `
* **Default**: true
EFP_DISP (EFP)
:ref:`apdx:EFP` |w---w| Do include dispersion energy term in EFP computation?
* **Type**: :ref:`boolean `
* **Default**: true
EFP_DISP_DAMPING (EFP)
:ref:`apdx:EFP` |w---w| Fragment-fragment dispersion damping type. ``TT`` is a damping formula by Tang and Toennies. ``OVERLAP`` is overlap-based dispersion damping.
* **Type**: string
* **Possible Values**: TT, OVERLAP, OFF
* **Default**: OVERLAP
EFP_ELST (EFP)
:ref:`apdx:EFP` |w---w| Do include electrostatics energy term in EFP computation?
* **Type**: :ref:`boolean `
* **Default**: true
EFP_ELST_DAMPING (EFP)
:ref:`apdx:EFP` |w---w| Fragment-fragment electrostatic damping type. ``SCREEN`` is a damping formula based on screen group in the EFP potential. ``OVERLAP`` is damping that computes charge penetration energy.
* **Type**: string
* **Possible Values**: SCREEN, OVERLAP, OFF
* **Default**: SCREEN
EFP_EXCH (EFP)
:ref:`apdx:EFP` |w---w| Do include exchange repulsion energy term in EFP computation?
* **Type**: :ref:`boolean `
* **Default**: true
EFP_POL (EFP)
:ref:`apdx:EFP` |w---w| Do include polarization energy term in EFP computation?
* **Type**: :ref:`boolean `
* **Default**: true
EFP_POL_DAMPING (EFP)
:ref:`apdx:EFP` |w---w| Fragment-fragment polarization damping type. ``TT`` is a damping formula like Tang and Toennies.
* **Type**: string
* **Possible Values**: TT, OFF
* **Default**: TT
PRINT (EFP)
:ref:`apdx:EFP` |w---w| The amount of information printed to the output file.
* **Type**: integer
* **Default**: 1
QMEFP_ELST (EFP)
:ref:`apdx:EFP` |w---w| Do include electrostatics energy term in QM/EFP computation?
* **Type**: :ref:`boolean `
* **Default**: true
QMEFP_POL (EFP)
:ref:`apdx:EFP` |w---w| Do include polarization energy term in EFP computation?
* **Type**: :ref:`boolean `
* **Default**: true
DISP_SIZE (FINDIF)
:ref:`apdx:FINDIF` |w---w| Displacement size in au for finite-differences.
* **Type**: double
* **Default**: 0.005
GRADIENT_WRITE (FINDIF)
:ref:`apdx:FINDIF` |w---w| Do write a gradient output file? If so, the filename will end in .grad, and the prefix is determined by |globals__writer_file_label| (if set), or else by the name of the output file plus the name of the current molecule.
* **Type**: :ref:`boolean `
* **Default**: false
HESSIAN_WRITE (FINDIF)
:ref:`apdx:FINDIF` |w---w| Do write a hessian output file? If so, the filename will end in .hess, and the prefix is determined by |globals__writer_file_label| (if set), or else by the name of the output file plus the name of the current molecule.
* **Type**: :ref:`boolean `
* **Default**: false
POINTS (FINDIF)
:ref:`apdx:FINDIF` |w---w| Number of points for finite-differences (3 or 5)
* **Type**: integer
* **Default**: 3
CUBIC_GRID_OVERAGE (FISAPT)
:ref:`apdx:FISAPT` |w---w| CubicScalarGrid spatial extent in bohr [O_X, O_Y, O_Z]. Defaults to 4.0 bohr each.
* **Type**: array
* **Default**: No Default
CUBIC_GRID_SPACING (FISAPT)
:ref:`apdx:FISAPT` |w---w| CubicScalarGrid grid spacing in bohr [D_X, D_Y, D_Z]. Defaults to 0.2 bohr each.
* **Type**: array
* **Default**: No Default
D_CONVERGENCE (FISAPT)
:ref:`apdx:FISAPT` |w---w| Convergence criterion for residual of the CPHF coefficients in the SAPT :math:`E_{ind,resp}^{(20)}` term.
* **Type**: :ref:`conv double `
* **Default**: 1e-8
FISAPT_CHARGE_COMPLETENESS (FISAPT)
:ref:`apdx:FISAPT` |w---w| Amount of fragment charge completeness to distinguish link bonds
* **Type**: double
* **Default**: 0.8
FISAPT_DO_FSAPT (FISAPT)
:ref:`apdx:FISAPT` |w---w| Do an F-SAPT analysis?
* **Type**: :ref:`boolean `
* **Default**: true
FISAPT_DO_PLOT (FISAPT)
:ref:`apdx:FISAPT` |w---w| Plot a scalar-field analysis
* **Type**: :ref:`boolean `
* **Default**: false
FISAPT_FSAPT_EXCH_SCALE (FISAPT)
:ref:`apdx:FISAPT` |w---w| Do F-SAPT exchange scaling? (ratio of S^\infty to S^2)
* **Type**: :ref:`boolean `
* **Default**: true
FISAPT_FSAPT_FILEPATH (FISAPT)
:ref:`apdx:FISAPT` |w---w| Filepath to drop F-SAPT data
* **Type**: string
* **Default**: fsapt/
FISAPT_FSAPT_IND_RESPONSE (FISAPT)
:ref:`apdx:FISAPT` |w---w| Do F-SAPT coupled response? (not recommended)
* **Type**: :ref:`boolean `
* **Default**: false
FISAPT_FSAPT_IND_SCALE (FISAPT)
:ref:`apdx:FISAPT` |w---w| Do F-SAPT induction scaling? (ratio of HF induction to F-SAPT induction)
* **Type**: :ref:`boolean `
* **Default**: true
FISAPT_FSSAPT_FILEPATH (FISAPT)
:ref:`apdx:FISAPT` |w---w| Filepath to drop sSAPT0 exchange-scaling F-SAPT data
* **Type**: string
* **Default**: s-fsapt/
FISAPT_LINK_ASSIGNMENT (FISAPT)
:ref:`apdx:FISAPT` |w---w| Where do sigma links go (to C or to AB)?
* **Type**: string
* **Possible Values**: C, AB
* **Default**: C
FISAPT_LINK_SELECTION (FISAPT)
:ref:`apdx:FISAPT` |w---w| Specification algorithm for link bonds in ISAPT
* **Type**: string
* **Possible Values**: AUTOMATIC, MANUAL
* **Default**: AUTOMATIC
FISAPT_MANUAL_LINKS (FISAPT)
:ref:`apdx:FISAPT` |w---w| Manual link bond specification [[Atom1, Atom2], ...]
* **Type**: array
* **Default**: No Default
FISAPT_PLOT_FILEPATH (FISAPT)
:ref:`apdx:FISAPT` |w---w| Filepath to drop scalar data
* **Type**: string
* **Default**: plot/
INTS_TOLERANCE (FISAPT)
:ref:`apdx:FISAPT` |w---w| Minimum absolute value below which integrals are neglected. For ISAPT, a variational collapse problem seems to occur for even rather modest values of this cutoff, when DF is used and when very close contacts occur. Therefore, we will be safe and turn it off (this does not affect performance overtly)
* **Type**: :ref:`conv double `
* **Default**: 0.0
LOCAL_CONVERGENCE (FISAPT)
:ref:`apdx:FISAPT` |w---w| Relative convergence in orbital localization
* **Type**: :ref:`conv double `
* **Default**: 1.0e-12
LOCAL_IBO_POWER (FISAPT)
:ref:`apdx:FISAPT` |w---w| IBO localization metric power
* **Type**: integer
* **Default**: 4
LOCAL_IBO_STARS (FISAPT)
:ref:`apdx:FISAPT` |w---w| IBO Centers for Pi Degeneracy
* **Type**: array
* **Default**: No Default
LOCAL_IBO_STARS_COMPLETENESS (FISAPT)
:ref:`apdx:FISAPT` |w---w| IBO Charge metric for classification as Pi
* **Type**: double
* **Default**: 0.90
LOCAL_IBO_USE_STARS (FISAPT)
:ref:`apdx:FISAPT` |w---w| IBO Stars procedure
* **Type**: :ref:`boolean `
* **Default**: false
LOCAL_MAXITER (FISAPT)
:ref:`apdx:FISAPT` |w---w| Maximum iterations in localization
* **Type**: integer
* **Default**: 1000
MAXITER (FISAPT)
:ref:`apdx:FISAPT` |w---w| Maximum number of iterations for CPHF
* **Type**: integer
* **Default**: 50
SSAPT0_SCALE (FISAPT)
:ref:`apdx:FISAPT` |w---w| Do sSAPT0 exchange-scaling with F-SAPT
* **Type**: :ref:`boolean `
* **Default**: false
ACTIVE_NAT_ORBS (FNOCC)
:ref:`apdx:FNOCC` |w---w| An array containing the number of virtual natural orbitals per irrep (in Cotton order) so a user can specify the number of retained natural orbitals rather than determining them with |fnocc__occ_tolerance|. This keyword overrides |fnocc__occ_tolerance| and |fnocc__occ_percentage|.
* **Type**: array
* **Default**: No Default
BRUECKNER_MAXITER (FNOCC)
:ref:`apdx:FNOCC` |w---w| Maximum number of iterations for Brueckner orbitals optimization
* **Type**: integer
* **Default**: 20
CC_SCALE_OS (FNOCC)
:ref:`apdx:FNOCC` |w---w| Oppposite-spin scaling factor for SCS-CCSD
* **Type**: double
* **Default**: 1.27
CC_SCALE_SS (FNOCC)
:ref:`apdx:FNOCC` |w---w| Same-spin scaling factor for SCS-CCSD
* **Type**: double
* **Default**: 1.13
CC_TIMINGS (FNOCC)
:ref:`apdx:FNOCC` |w---w| Do time each cc diagram?
* **Type**: :ref:`boolean `
* **Default**: false
CEPA_NO_SINGLES (FNOCC)
:ref:`apdx:FNOCC` |w---w| Flag to exclude singly excited configurations from a coupled-pair computation.
* **Type**: :ref:`boolean `
* **Default**: false
CHOLESKY_TOLERANCE (FNOCC)
:ref:`apdx:FNOCC` |w---w| tolerance for Cholesky decomposition of the ERI tensor
* **Type**: :ref:`conv double `
* **Default**: 1.0e-4
DFCC (FNOCC)
:ref:`apdx:FNOCC` |w---w| Do use density fitting or cholesky decomposition in CC? This keyword is used internally by the driver. Changing its value will have no effect on the computation.
* **Type**: :ref:`boolean `
* **Default**: false
DF_BASIS_CC (FNOCC)
:ref:`apdx:FNOCC` |w---w| Auxilliary basis for df-ccsd(t).
* **Type**: string
* **Possible Values**: :ref:`basis string `
* **Default**: No Default
DIIS_MAX_VECS (FNOCC)
:ref:`apdx:FNOCC` |w---w| Desired number of DIIS vectors
* **Type**: integer
* **Default**: 8
DIPMOM (FNOCC)
:ref:`apdx:FNOCC` |w---w| Compute the dipole moment? Note that dipole moments are only available in the FNOCC module for the ACPF, AQCC, CISD, and CEPA(0) methods.
* **Type**: :ref:`boolean `
* **Default**: false
E_CONVERGENCE (FNOCC)
:ref:`apdx:FNOCC` |w---w| Convergence criterion for CC energy. See Table :ref:`Post-SCF Convergence ` for default convergence criteria for different calculation types. Note that convergence is met only when |fnocc__e_convergence| and |fnocc__r_convergence| are satisfied.
* **Type**: :ref:`conv double `
* **Default**: 1.0e-6
MAXITER (FNOCC)
:ref:`apdx:FNOCC` |w---w| Maximum number of CC iterations
* **Type**: integer
* **Default**: 100
MP2_SCALE_OS (FNOCC)
:ref:`apdx:FNOCC` |w---w| Opposite-spin scaling factor for SCS-MP2
* **Type**: double
* **Default**: 1.20
MP2_SCALE_SS (FNOCC)
:ref:`apdx:FNOCC` |w---w| Same-spin scaling factor for SCS-MP2
* **Type**: double
* **Default**: 1.0/3.0
NAT_ORBS (FNOCC)
:ref:`apdx:FNOCC` |w---w| Do use MP2 NOs to truncate virtual space for QCISD/CCSD and (T)?
* **Type**: :ref:`boolean `
* **Default**: false
OCC_PERCENTAGE (FNOCC)
:ref:`apdx:FNOCC` |w---w| Cutoff for occupation of MP2 virtual NOs in FNO-QCISD/CCSD(T). The number of virtual NOs is chosen so the occupation of the truncated virtual space is |fnocc__occ_percentage| percent of occupation of the original MP2 virtual space. This option is only used if |fnocc__nat_orbs| = true. This keyword overrides |fnocc__occ_tolerance|.
* **Type**: double
* **Default**: 99.0
OCC_TOLERANCE (FNOCC)
:ref:`apdx:FNOCC` |w---w| Cutoff for occupation of MP2 virtual NOs in FNO-QCISD/CCSD(T). Virtual NOs with occupations less than |fnocc__occ_tolerance| will be discarded. This option is only used if |fnocc__nat_orbs| = true.
* **Type**: :ref:`conv double `
* **Default**: 1.0e-6
R_CONVERGENCE (FNOCC)
:ref:`apdx:FNOCC` |w---w| Convergence for the CC amplitudes. Note that convergence is met only when |fnocc__e_convergence| and |fnocc__r_convergence| are satisfied.
* **Type**: :ref:`conv double `
* **Default**: 1.0e-7
SCS_CCSD (FNOCC)
:ref:`apdx:FNOCC` |w---w| Do SCS-CCSD?
* **Type**: :ref:`boolean `
* **Default**: false
SCS_CEPA (FNOCC)
:ref:`apdx:FNOCC` |w---w| Do SCS-CEPA? Note that the scaling factors will be identical to those for SCS-CCSD.
* **Type**: :ref:`boolean `
* **Default**: false
SCS_MP2 (FNOCC)
:ref:`apdx:FNOCC` |w---w| Do SCS-MP2?
* **Type**: :ref:`boolean `
* **Default**: false
TRIPLES_LOW_MEMORY (FNOCC)
:ref:`apdx:FNOCC` |w---w| Do use low memory option for triples contribution? Note that this option is enabled automatically if the memory requirements of the conventional algorithm would exceed the available resources
* **Type**: :ref:`boolean