Test Suite and Sample Inputs¶
PSI4 is distributed with an extensive test suite, which can
be found in psi4/tests. After building the source code, these
can automatically be run by running ctest
in the compilation
directory. More info on ctest
options can be found
here. Sample input files
can be found in the psi4/samples subdirectory of the toplevel Psi
directory. The samples and a brief description are provided below.
Sample inputs accessible through interfaced executables are bulleted below.
Sample inputs for PSI4 as distributed are below.
Input File 
Description 

OMP3 ccpVDZ gradient for the NO radical 

DC06 calculation for the O2 molecule (triplet ground state). This performs geometry optimization using twostep and simultaneous solution of the response equations for the analytic gradient. 

TDHF test variable access 

Vibrational and thermo analysis of water trimer (geometry from J. Chem. Theory Comput. 11, 21262136 (2015)) 

tdwb97x singlet excitation energies of methylene (tda) 

Test QCISD(T) for H2O/ccpvdz Energy 

SCF DZ finite difference frequencies by gradients for C4NH4 

DFOMP2.5 ccpVDZ energy for the H2O+ cation 

tduhf test on triplet states of methylene (rpa) 

ZAPT(n)/631G NH2 Energy Point, with n=225 

RHF orbitals and density for water. 

RHFCC2LR/ccpVDZ optical rotation of H2O2. gauge = length, omega= (589 355 nm) 

RHFCC2LR/ccpVDZ dynamic polarizabilities of HOF molecule. 

CC3(ROHF)/ccpVDZ H2O \(R_e\) geom from Olsen et al., JCP 104, 8007 (1996) 

Advanced python example sets different sets of scf/postscf conv crit and check to be sure computation has actually converged to the expected accuracy. 

check that CC is returning the same values btwn CC*, FNOCC, and DFOCC modules 

OMP2 ccpVDZ energy for the NO molecule. 

analog of fsaptextabc with molecule and external potentials in Bohr 

SCF DZ allene geometry optimzation, with Cartesian input 

Test individual integral objects for correctness. 

tdcamb3lyp with DiskDF and method/basis specification 

Sample UHF/631G** CH2 computation 

testing aligner on enantiomers based on Table 1 of 10.1021/ci100219f aka J Chem Inf Model 2010 50(12) 21292140 

Computation of CPcorrected water trimer gradient (geometry from J. Chem. Theory Comput. 11, 21262136 (2015)) 

UFH and B3LYP ccpVQZ properties for the CH2 molecule. 

Tests analytic CC2 gradients 

FSAPT0/junccpvdz procedure for methane dimer 

SAPT(DFT) augccpVDZ computation for the water dimer interaction energy. 

DF SCF 631G analytical vs finitedifference tests Tests DF UHF hessian code for Ca != Cb 

Frozencore CCSD(T)/ccpVDZ on C4H4N anion with disk ao algorithm 

Example of stateaveraged CASSCF for the C2 molecule see C. D. Sherrill and P. Piecuch, J. Chem. Phys. 122, 124104 (2005) 

DSDPBEP86 S22 Ammonia test 

RHF orbitals and density for water. 

CI/MCSCF ccpvDZ properties for Potassium nitrate (rocket fuel!) 

OMP2.5 ccpVDZ gradient for the NO radical 

SCF STO3G geometry optimzation, with Zmatrix input 

ADC(2)/augccpVDZ on two water molecules that are distant from 1000 angstroms from each other 

Superficial test of PubChem interface 

Check flavors of B3LYP (b3lyp3/b3lyp5) against other programs 

MkMRCCSD(T) single point. \(^1A_1\) CH2 state described using the Ms = 0 component of the singlet. Uses RHF singlet orbitals. 

Test Gibbs free energies at 298 K of N2, H2O, and CH4. 

Tests CCENERGY’s CCSD gradient in the presence of a dipole field 

CASSCF/631G** energy point 

Sample UHF/ccpVDZ H2O computation on a doublet cation, using RHF/ccpVDZ orbitals for the closedshell neutral as a guess 

Single point gradient of 12B1 state of H2O+ with EOMCCSD 

631G(d) optimization of SF4 starting from linear bond angle that is not linear in the optimized structure but is in a symmetry plane of the molecule. 

631G H2O Test FCI Energy Point 

ADC(2)/631G** on H2O using builtin ADC module 

DC06 calculation for the He dimer. This performs a simultaneous update of the orbitals and cumulant, using DIIS extrapolation. Fourvirtual integrals are handled in the AO Basis, using integrals stored on disk. 

RHF ccpVDZ energy for water, automatically scanning the symmetric stretch and bending coordinates using Python’s builtin loop mechanisms. The geometry is specified using a Zmatrix with variables that are updated during the potential energy surface scan, and then the same procedure is performed using polar coordinates, converted to Cartesian coordinates. 

MOM excitation from LUMO HOMO+4 

Analytic vs. finite difference DFSCF frequency test for water. 

Various constrained energy minimizations of HOOH with ccpvdz RHF. Cartesiancoordinate constrained optimizations of HOOH in Cartesians. 

Allelectron MP2 631G** geometry optimization of water 

Test initial SCF guesses on FH and FH+ in ccpVTZ basis 

DFCCSD ccpVDZ gradients for the H2O molecule. 

Frozencore CCSD(ROHF)/ccpVDZ on CN radical with diskbased AO algorithm 

Benzene Dimer DFHF/ccpVDZ 

EOMCC3(UHF) on CH radical with userspecified basis and properties for particular root 

DFOMP2.5 ccpVDZ gradients for the H2O+ cation. 

MP3 ccpVDZ gradient for the NO radical 

UHFODC12 and RHFODC12 singlepoint energy for H2O. This performs a simultaneous update of orbitals and cumulants, using DIIS extrapolation. Fourvirtual integrals are handled in the AO basis, where integral transformation is avoided. In the next RHFODC12 computation, AO_BASIS=NONE is used, where fourvirtual integrals are transformed into MO basis. 

631G* C2 Test RASCI Energy Point, testing two different ways of specifying the active space, either with the ACTIVE keyword, or with RAS1, RAS2, RESTRICTED_DOCC, and RESTRICTED_UOCC 

check nonphysical masses possible 

DFT integral algorithms test, performing wB97 RKS and UKS computations on water and its cation, using all of the different integral algorithms. This tests both the ERI and ERF integrals. 

Various gradients for a strained helium dimer and water molecule 

Tests RHF/ROHF/UHF SCF gradients 

B3LYP ccpVDZ geometry optimzation of phenylacetylene, starting from not quite linear structure updated reference due to new BraggSlater radii 

RHF ccpVQZ energy for the BH molecule, with Cartesian input. 

Compute three IP and 2 EA’s for the PH3 molecule 

Dispersionless density functional (dlDF+D) internal match to Psi4 Extensive testing has been done to match supplemental info of Szalewicz et. al., Phys. Rev. Lett., 103, 263201 (2009) and Szalewicz et. al., J. Phys. Chem. Lett., 1, 550555 (2010) 

Tests RHF CCSD(T)gradients 

OMP2 ccpVDZ gradient for the NO radical 

SAPT0(ROHF) openshell computation of CN  Ne interaction energy First with junccpVDZ and density fitted integrals with ROHF Then with ccpVDZ and direct integrals, except for dispersion that is computed with ccpVDZri density fitting with ROHF. 

MkMRCCSD single point. \(^3 \Sigma ^\) O2 state described using the Ms = 0 component of the triplet. Uses ROHF triplet orbitals. 

Maximum Overlap Method (MOM) Test. MOM is designed to stabilize SCF convergence and to target excited Slater determinants directly. 

DFSCF ccpVDZ of benzenehydronium ion, scanning the dissociation coordinate with Python’s builtin loop mechanism. The geometry is specified by a Zmatrix with dummy atoms, fixed parameters, updated parameters, and separate charge/multiplicity specifiers for each monomer. Oneelectron properties computed for dimer and one monomer. 

Test of SAD/Castup (mainly not dying due to file weirdness) 

test FCIDUMP functionality for rhf/uhf 

Test FNODFCCSD(T) energy 

ccpvdz H2O Test coupledpair CISD against DETCI CISD 

Single point energies of multiple excited states with EOMCCSD 

External potential calculation involving a TIP3P water and a QM water. Finite different test of the gradient is performed to validate forces. 

Test FNODFCCSD(T) energy 

SCF DZ finite difference frequencies by energies for C4NH4 

CCSD dipole with userspecified basis set 

Tests CAM gradients with and without XC pieces to narrow grid error 

SAPT(DFT) augccpVDZ interaction energy between Ne and Ar atoms. 

631G H2O Test FCI Energy Point 

Test parsed and exotic calls to energy() like zapt4, mp2.5, and cisd are working 

RHFCCSD(T) ccpVQZ frozencore energy of the BH molecule, with Cartesian input. This version tests the FROZEN_DOCC option explicitly 

Test of the superposition of atomic densities (SAD) guess, using a highly distorted water geometry with a ccpVDZ basis set. This is just a test of the code and the user need only specify guess=sad to the SCF module’s (or global) options in order to use a SAD guess. The test is first performed in C2v symmetry, and then in C1. 

MkMRPT2 single point. \(^1A_1\) F2 state described using the Ms = 0 component of the singlet. Uses TCSCF singlet orbitals. 

DFMP2 frequency by difference of energies for H2O 

EOMCC3/ccpVTZ on H2O 

RASCI/631G** H2O Energy Point 

Sample HF/ccpVDZ H2O computation all derivatives 

Cholesky filter a complete basis 

SAPT(DFT) augccpVDZ interaction energy between Ne and Ar atoms. 

SCF with various combinations of pk/densityfitting, castup/nocastup, and spherical/cartesian settings. Demonstrates that puream setting is getting set by orbital basis for all df/castup parts of calc. Demonstrates that answer doesn’t depend on presence/absence of castup. Demonstrates (by comparison to castup2) that output file doesn’t depend on options (scf_type) being set global or local. This input uses local. 

EOMCC3(ROHF) on CH radical with userspecified basis and properties for particular root 

SAPT(DFT) augccpVDZ interaction energy between Ne and Ar atoms. 

Vibrational and thermo analysis of several water isotopologs. Demonstrates Hessian reuse for different temperatures and pressures but not for different isotopologs. 

Internal match to psi4, test to match to literature values in litref.in/litref.out 

metaGGA gradients of water and ssh molecules reference gradients updated due to new BraggSlater radii 

Frequencies for H2O B3LYP/631G* at optimized geometry 

Various basis set extrapolation tests 

MP2.5 ccpVDZ gradient for the NO radical 

The multiple guesses for DCT amplitudes for ODC12. 

Example potential energy surface scan and CPcorrection for Ne2 

Unrestricted DFDCT ODC12 gradient for O2 with ccpVTZ/ccpVTZRI standard/auxiliary basis set 

Quick test of external potential in FSAPT (see fsapt1 for a real example) 

Electrostatic potential and electric field evaluated on a grid around water. 

RHFCCSD(T) ccpVQZ frozencore energy of the BH molecule, with Cartesian input. After the computation, the checkpoint file is renamed, using the PSIO handler. 

RHFCC2LR/ccpVDZ static polarizabilities of HOF molecule. 

RHF CCSD(T) augccpvtz frozencore energy of C4NH4 Anion 

Density fitted MP2 ccPVDZ/ccpVDZRI computation of formic acid dimer binding energy using explicit specification of ghost atoms. This is equivalent to the dfmp2_1 sample but uses both (equivalent) specifications of ghost atoms in a manual counterpoise correction. 

MOM excitation from LUMO HOMO+3 

MkMRCCSD(T) single point. \(^1A_1\) O$_3` state described using the Ms = 0 component of the singlet. Uses TCSCF orbitals. 

631G** H2O Test RASSCF Energy Point will default to only singles and doubles in the active space 

usapt example with empty beta due to frozen core 

Example SAPT computation for ethene*ethine (i.e., ethylene*acetylene), test case 16 from the S22 database 

CC3(UHF)/ccpVDZ H2O \(R_e\) geom from Olsen et al., JCP 104, 8007 (1996) 

Test of the superposition of atomic densities (SAD) guess, using a highly distorted water geometry with a ccpVDZ basis set. This is just a test of the code and the user need only specify guess=sad to the SCF module’s (or global) options in order to use a SAD guess. The test is first performed in C2v symmetry, and then in C1. 

apply linear fragmentation algorithm to a water cluster 

Optimization followed by frequencies H2O HF/ccpVDZ 

CASSCF/631G** energy point. Check energy with frozen core/virtual orbs. after semicanonicalization. 

Restricted DFDCT ODC12 gradient for ethylene with ccpVDZ/ccpVDZRI standard/auxiliary basis set 

SAPT2+(3) augccpVDZ computation of the formamide dimer interaction energy, using the augccpVDZJKFIT DF basis for SCF and augccpVDZRI for SAPT. This example uses frozen core as well as MP2 natural orbital approximations. 

He2+ FCI/ccpVDZ Transition Dipole Moment 

Intercalls among python wrappers database, cbs, optimize, energy, etc. Though each call below functions individually, running them all in sequence or mixing up the sequence is aspirational at present. Also aspirational is using the intended types of gradients. 

SCF STO3G geometry optimzation, with Zmatrix input, by finitedifferences 

DFCCDL ccpVDZ energy for the H2O molecule. 

Tests SAPT0D corrections, with a variety of damping functions/parameters 

RHF CCSD(T) STO3G frozencore energy of C4NH4 Anion 

Test SAD SCF guesses on noble gas atom 

Compute the dipole, quadrupole, and traceless quadrupoles for water. 

CCSD/ccpVDZ dipole polarizability at two frequencies 

OMP3 ccpVDZ energy for the H2O molecule 

ROHF frontier orbitals of CH2(s) and CH2(t). 

RHF augccpVQZ energy for the BH molecule, with Cartesian input. Various gradients for a strained helium dimer and water molecule 

Test of SFX2C1e on water uncontracted ccpVDZDK The reference numbers are from Lan Cheng’s implementation in Cfour 

RHF interaction energies using nbody and cbs parts of the driver Ne dimer with mp2/v[dt]z + d:ccsd(t)/vdz 

SAPT0 ccpVDZ computation of the etheneethyne interaction energy, using the ccpVDZJKFIT RI basis for SCF and ccpVDZRI for SAPT. Monomer geometries are specified using Cartesian coordinates. 

631G** H2O Test CISD Energy Point with subspace collapse 

DFOMP3 ccpVDZ energy for the H2O+ cation 

DFT (LDA/GGA) test of custom implementations in: gga_superfuncs.py 

OMP2.5 ccpVDZ energy for the H2O molecule. 

MBIS calculation on H2O 

SAPT(DFT) augccpVDZ interaction energy between Ne and Ar atoms. 

sapt example with orbital freezing with alkali metal and dMP2 

DFOMP3 ccpVDZ gradients for the H2O molecule. 

Extrapolated water energies  conventional integrals version 

OMP2 ccpVDZ energy for the NO molecule. 

comparison of DFMP2 and DLPNOMP2 with a CBS extrapolation 

BH single points, checking that program can run multiple instances of DETCI in a single input, without an intervening clean() call 

Kr–Kr nocp energies with allelectron basis set to check frozen core 

OLCCD ccpVDZ energy for the H2O molecule. 

MP2/augccpvDZ many body energies of an arbitrary Helium complex, addressing 4body formulas 

Test of SFX2C1e on Water ccpVDZDK. In this test the Dirac equation is solved in the uncontracted ccpVDZDK basis. The reference numbers are from Lan Cheng’s implementation in Cfour 

SCF/ccpVDZ optimization example with frozen cartesian 

DFMP2 ccpVDZ gradient for the NO molecule. 

Test if the the guess read in the same basis converges. 

Density fitted MP2 ccPVDZ/ccpVDZRI computation of formic acid dimer binding energy using automatic counterpoise correction. Monomers are specified using Cartesian coordinates. 

ROHF stability analysis check for CN with ccpVDZ. This test corresponds to the rohfstab test from Psi3. 

SCF ccpVDZ geometry optimzation of ketene, starting from bent structure 

SCSOMP2 ccpVDZ geometry optimization for the H2O molecule. 

tdwb97x excitation energies of singlet states of h2o, wfn passing 

This is a shorter version if isapt1  does not do cube plots. See isapt1 for full details 

CCSD/sto3g optical rotation calculation (length gauge only) at two frequencies on methyloxirane 

optimization with method defined via cbs 

RHFCC2LR/STO3G optical rotation of (S)methyloxirane. gauge = length, omega = (589 355 nm) 

Ne atom RASCI/ccpVQZ Example of splitvirtual CISD[TQ] from Sherrill and Schaefer, J. Phys. Chem. XXX This uses a “primary” virtual space 3s3p (RAS 2), a “secondary” virtual space 3d4s4p4d4f (RAS 3), and a “tertiary” virtual space consisting of the remaining virtuals. First, an initial CISD computation is run to get the natural orbitals; this allows a meaningful partitioning of the virtual orbitals into groups of different importance. Next, the RASCI is run. The splitvirtual CISD[TQ] takes all singles and doubles, and all triples and quadruples with no more than 2 electrons in the secondary virtual subspace (RAS 3). If any electrons are present in the tertiary virtual subspace (RAS 4), then that excitation is only allowed if it is a single or double. 

DFSCF ccpVDZ multipole moments of benzene, up to 7th order and electrostatic potentials evaluated at the nuclear coordinates 

Single point energies of multiple excited states with EOMCCSD 

OMP2 ccpVDZ energy for the H2O molecule. 

Database calculation, run in sow/reap mode. 

H2O CISD/631G** Optimize Geometry by Energies 

OLCCD ccpVDZ freqs for C2H2 

usapt example with empty beta 

DFMP2 ccpVDZ gradient for the NO molecule. 

LCCD ccpVDZ gradient for the H2O molecule. 

MkMRCCSD frequencies. \(^1A_1\) O$_3` state described using the Ms = 0 component of the singlet. Uses TCSCF orbitals. 

Test if the the guess read in the same basis converges. 

ROHFEOMCCSD/DZ analytic gradient lowest \(^{2}B_1\) state of H2O+ (A1 excitation) 

DFOMP2.5 ccpVDZ gradients for the H2O molecule. 

CONV SCF 631G analytical vs finitedifference tests Tests UHF hessian code for Ca != Cb 

CCSD/ccpVDZ optical rotation calculation (length gauge only) on Zmat H2O2 

Finite difference of gradients frequency, run in sow/reap mode. 

ROHFCCSD/ccpVDZ \(^{3}B_1\) CH2 geometry optimization via analytic gradients 

MBIS calculation on H2O 

Test computing values of basis functions (puream and nonpuream) at points 

RHF STO3G dipole moment computation, performed by applying a finite electric field and numerical differentiation. 

Tests the Psi4 SFSAPT code 

DFT Functional Test for RangeSeperated Hybrids and Ghost atoms 

EOMCCSD/ccpVDZ on H2O2 with two excited states in each irrep 

Test frequencies by finite differences of energies for planar C4NH4 TS 

DF SCF 631G UHFl vs RHF test Tests DF UHF hessian code for Ca = Cb 

UHFCCSD/ccpVDZ \(^{3}B_1\) CH2 geometry optimization via analytic gradients 

Matches Table II aCCSD(T)/ccpVDZ H2O @ 2.5 * Re value from Crawford and Stanton, IJQC 98, 601611 (1998). 

Computation of VMFCcorrected HF dimer Hessian 

Compute the IRC for HOOH torsional rotation at the RHF/DZP level of theory. 

Transitionstate optimizations of HOOH to both torsional transition states. 

DSD S22 Ammonia test 

RHFEOMCC2/ccpVDZ lowest two states of each symmetry of H2O. 

Check that C++ Molecule class and qcdb molecule class are reading molecule input strings identically 

OLCCD ccpVDZ energy with B3LYP initial guess for the NO radical 

EOMCC2/ccpVDZ on H2O2 with two excited states in each irrep 

DFT Functional Test 

MP3 ccpVDZ gradient for the H2O molecule. 

checks that all SAPT physical components (elst, exch, indc, disp) and total IE are being computed correctly for SAPT2+3(CCD)dMP2/augccpvdz and all lesser methods thereof. 

OMP3 ccpVDZ gradient for the H2O molecule. 

ADIIS test case, from 10.1063/1.3304922 

run some BLAS benchmarks 

RKS Density Matrix basedIntegral Screening Test for benzene 

DFCCSD(T) ccpVDZ energy for the H2O molecule. 

WaterArgon complex with ECP present; check of energies and forces. 

SAPT2+3 with S^inf exchind30 Geometries taken from the S66x10 database, the shortestrange point (R = 0.7 R_e) 

Fractional occupation with symmetry 

DFCCSD(T) ccpVDZ gradients for the H2O molecule. 

RHFCC2LR/ccpVDZ optical rotation of H2O2. gauge = both, omega = (589 355 nm) 

RHFODC12 analytic gradient computations for H2O use AO_BASIS=DISK and AO_BASIS=NONE, respectively. RHFODC06 analytic gradient computations for H2O use AO_BASIS=DISK and AO_BASIS=NONE, respectively. 

Multifragment opt of C2h methane dimer with usercombined reference points. 

check all variety of options parsing 

DFCCSD ccpVDZ energy for the H2O molecule. 

MBIS calculation on OH (Expanded Arrays) 

Benzene Dimer OutofCore HF/ccpVDZ 

Test FNOQCISD(T) computation 

Test omega is setable updated wb97x_20,wb97x_03 to account for new BraggSlater radii 

routing check on lccd, lccsd, cepa(0). 

Various constrained energy minimizations of HOOH with ccpvdz RHF Internalcoordinate constraints in internalcoordinate optimizations. 

DFOMP2.5 ccpVDZ energy for the H2O molecule. 

ROHFCCSD(T) ccpVDZ frozencore energy for the \(^2\Sigma^+\) state of the CN radical, with Cartesian input. 

Test SCF dipole derivatives against old Psi3 reference values 

Optimize H2O HF/ccpVDZ 

LibXC density screening test. Tests empty, Conly, Xonly and XC superfunctionals. ‘super_mix’ showcases how to use different screening values for X and C parts. SCF will fail or crash (nans) without screening! 

EDIIS test case from 10.1063/1.1470195 

EOMCCSD/631g excited state transition data for water cation 

UHF gradient for a oneelectron system (no beta electrons). 

DFOMP3 ccpVDZ gradients for the H2O+ cation. 

Tests DFMP2 gradient in the presence of a dipole field 

DFMP2 ccpVDZ gradients for the H2O molecule. 

Compute the dipole polarizability for water with custom basis set. 

SAPT0 openshell computation of H2OHO2 interaction energy First with ccpVDZ and density fitted integrals with UHF Then with 631g and direct integrals, except for dispersion that is computed with ccpVDZri density fitting with UHF. 

Test of all different algorithms and reference types for SCF, on singlet and triplet O2, using the ccpVTZ basis set. 

DFBP86D2 ccpVDZ frozen core gradient of S22 HCN updated ref gradient due to new BraggSlater radii 

DFT (hybrids) test of implementations in: hybrid_superfuncs.py 

WaterArgon complex with ECP present; check of UHF Hessian 

DFT Functional Smoke Test 

CASSCF/631G** energy point 

MP2/augccpv[DT]Z many body energies of an arbitrary Helium complex Size vs cost tradeoff is rough here 

DFOMP3 ccpVDZ energy for the H2O molecule. 

This test case shows an example of running and analyzing a standard FSAPT0/junccpvdz procedure for HSG18dimer from the HSG database. 

Generation of NBO file 

tdcamb3lyp with DiskDF and method/basis specification 

MP(n)/augccpVDZ BH Energy Point, with n=219. Compare against M. L. Leininger et al., J. Chem. Phys. 112, 9213 (2000) 

UHF>UHF stability analysis test for BH with ccpVDZ Test direct SCF with and without symmetry, test PK without symmetry 

ROHF 631G** energy of the \(^{3}B_1\) state of CH2, with Zmatrix input. The occupations are specified explicitly. 

DFCCSDL ccpVDZ energy for the H2O molecule. 

RISCF ccpVTZ energy of water, with Zmatrix input and ccpVTZRI auxilliary basis. 

Compute the IRC for HCN <> NCH interconversion at the RHF/DZP level of theory. 

DFCCD ccpVDZ energy for the H2O molecule. 

check SP basis Fortran exponent parsing 

CC3/ccpVDZ H2O \(R_e\) geom from Olsen et al., JCP 104, 8007 (1996) 

ROHF and UHFBCCD(T)/ccpVDZ \(^{3}B_1\) CH2 singlepoint energy (fzc, MObasis \(\langle abcd \rangle\) ) 

OMP2 ccpVDZ energy for the H2O molecule. 

MP2.5 ccpVDZ gradient for the H2O molecule. 

H2 with tiny basis set, to test basis set parser’s handling of integers 

force occupations in scf 

Test SFX2C1e with a static electric field on He augccpVTZ 

631G** H2O+ Test CISD Energy Point 

DFT custom functional test 

OMP2.5 ccpVDZ gradient for the H2O molecule. 

ROHFEOMCCSD/DZ on the lowest two states of each irrep in \(^{3}B_1\) CH2. 

Example of stateaveraged CASSCF for the C2 molecule 

RHF/ccpvdzdecontract HCl singlepoint energy Testing the in line decontract option for basis sets 

DCT calculation for the NH3+ radical using the ODC12 and ODC13 functionals. This performs both simultaneous and QC update of the orbitals and cumulant using DIIS extrapolation. Fourvirtual integrals are first handled in the MO Basis for the first two energy computations. In the next computation ao_basis=disk algorithm is used, where the transformation of integrals for fourvirtual case is avoided. 

CCSD Response for H2O2 

Test of the superposition of atomic densities (SAD) guess, using a highly distorted water geometry with a ccpVDZ basis set. This is just a test of the code and the user need only specify guess=sad to the SCF module’s (or global) options in order to use a SAD guess. The test is first performed in C2v symmetry, and then in C1. 

HF and DFT variants singlepoints on zmat methane, mostly to test that PSI variables are set and computed correctly. Now also testing that CSX harvesting PSI variables correctly update ref_dft_2e/xc due to new BraggSlater radii 

A test of the basis specification. Various basis sets are specified outright and in blocks, both orbital and auxiliary. Constructs libmints BasisSet objects through the constructor that calls qcdb.BasisSet infrastructure. Checks that the resulting bases are of the right size and checks that symmetry of the Molecule observes the basis assignment to atoms. 

631G** H2O+ Test CISD Energy Point 

MP2 with a PBE0 reference computation 

Computation of NoCPcorrected water trimer gradient (geometry from J. Chem. Theory Comput. 11, 21262136 (2015)) 

comparison of DFMP2 and DLPNOMP2 

RHF Linear Exchange Algorithm test for water 

SOSOMP3 ccpVDZ geometry optimization for the H2O molecule. 

631G** H2O+ Test CISD Energy Point 

OMP2 ccpVDZ energy for the NO molecule. 

Single point gradient of 11B2 state of H2O with EOMCCSD 

Accesses basis sets, databases, plugins, and executables in noninstall locations 

TCSCF ccpVDZ energy of asymmetrically displaced ozone, with Zmatrix input. 

tduhf test on triplet states of methylene (tda), wfn passing 

check that methods can act on single atom 

RKS Linear Exchange Algorithm test for benzene 

HF/ccpVDZ many body energies of an arbitrary noble gas trimer complex Size vs cost tradeoff is rough here 

This checks that all energy methods can run with a minimal input and set symmetry. 

FSAPT with external charge on dimer 

SCF STO3G finitedifference frequencies from energies for H2O 

DFBP86D2 ccpVDZ frozen core gradient of S22 HCN update ref gradient due to new BraggSlater radii 

SCF/sto3g optimization with a hessian every step 

FSAPT0/junccpvdz procedure for methane dimer 

DFT JK ondisk test 

SCF STO3G finitedifferences frequencies from gradients for H2O 

RHFBCCD(T)/631G** H2O singlepoint energy (fzc, MObasis \(\langle abcd \rangle\)) 

EOMCCSD/631g excited state transition data for water with two excited states per irrep 

Tests RHF CCSD(T)gradients 

Vibrational and thermo analysis of several water isotopologs. Demonstrates Hessian reuse for different temperatures, pressures, and isotopologs 

Singlepoint gradient, analytic and via finitedifferences of 21A1 state of H2O with EOMCCSD 

DC06, DC12, ODC06 and ODC12 calculation for the He dimer. This performs a simultaneous update of the orbitals and cumulant, using DIIS extrapolation. Fourvirtual integrals are handled in the MO Basis. 

OLCCD ccpVDZ gradient for the NO radical 

OMP2 ccpVDZ energy for the NO radical 

SAPT calculation on bimolecular complex where monomers are unspecified so driver autofragments it. Basis set and auxiliary basis sets are assigned by atom type. 

Extrapolated water energies  densityfitted version 

Database calculation, so no molecule section in input file. Portions of the full databases, restricted by subset keyword, are computed by sapt0 and dfmp2 methods. 

DFMP2 ccpVDZ gradients for the H2O molecule. 

DCT calculation for the triplet O2 using DC06 and DC12. Only twostep algorithm is tested. 

Check that basis sets can be input with explicit angular momentum format 

CCSD/ccpVDZ optical rotation calculation (both gauges) on Cartesian H2O2 

Gradient regularized asymptotic correction (GRAC) test. 

DCT calculation for the HF+ using DC06 functional. This performs both twostep and simultaneous update of the orbitals and cumulant using DIIS extrapolation. Fourvirtual integrals are first handled in the MO Basis for the first two energy computations. In the next two the ao_basis=disk algorithm is used, where the transformation of integrals for fourvirtual case is avoided. The computation is then repeated using the DC12 functional with the same algorithms. 

Test that Python Molecule class processes geometry like psi4 Molecule class. 

MkMRCCSD(T) single point. \(^1A_1\) CH2 state described using the Ms = 0 component of the singlet. Uses RHF singlet orbitals. 

incremental Cholesky filtered SCF 

UHFCCSD(T) ccpVDZ frozencore energy for the \(^2\Sigma^+\) state of the CN radical, with Zmatrix input. 

SCF ccpVTZ geometry optimzation, with Zmatrix input 

Compute three IP and 2 EA’s for the PH3 molecule 

ROHFCCSD ccpVDZ frozencore energy for the \(^2\Sigma^+\) state of the CN radical, with Cartesian input. 

conventional and densityfitting mp2 test of mp2 itself and setting scsmp2 

Secondorder SCF convergnece: Benzene 

OMP2 ccpVDZ energy with ROHF initial guess orbitals for the NO radical 

Tests SCF gradient in the presence of a dipole field 

UHF and ROHF Linear Exchange Algorithm test for benzyl cation 

UHF STO3G (Cartesian) and ccpVDZ (spherical) water Hessian test, against Psi3 reference values. This test should match RHF values exactly 

MP2 ccpvDZ properties for Nitrogen oxide 

Various extrapolated optimization methods for the H2 molecule 

DFT Functional Test 

Various constrained energy minimizations of HOOH with ccpvdz RHF. Cartesiancoordinate constrained optimizations of HOOH in internals. 

631G** UHF CH2 3B1 optimization. Uses a ZMatrix with dummy atoms, just for demo and testing purposes. 

Computation of VMFCcorrected water trimer Hessian (geometry from J. Chem. Theory Comput. 11, 21262136 (2015)) 

A demonstration of mixed Cartesian/ZMatrix geometry specification, using variables, for the benzenehydronium complex. Atoms can be placed using ZMatrix coordinates, whether they belong to the same fragment or not. Note that the Cartesian specification must come before the ZMatrix entries because the former define absolute positions, while the latter are relative. 

Omega optimization for LRC functional wB97 on water 

SCF DZ allene geometry optimization, with Cartesian input, first in c2v symmetry, then in Cs symmetry from a starting point with a nonlinear central bond angle. 

631G H2O Test FCI Energy Point 

ROHFEOMCCSD/DZ analytic gradient lowest \(^{2}A_1\) excited state of H2O+ (B1 excitation) 

MkMRCCSD(T) single point. \(^1A_1\) CH2 state described using the Ms = 0 component of the singlet. Uses RHF singlet orbitals. 

NeXe dimer MP2 energies with ECP, with electrons correlated then frozen. 

SCSOMP3 ccpVDZ geometry optimization for the H2O molecule. 

External potential calculation involving a TIP3P water and a QM water for DFMP2. Finite different test of the gradient is performed to validate forces. 

Tests to determine full point group symmetry. Currently, these only matter for the rotational symmetry number in thermodynamic computations. 

MBIS calculation on ZnO 

cc3: RHFCCSD/631G** H2O geometry optimization and vibrational frequency analysis by finitedifferences of gradients 

This test case shows an example of running and analyzing a difference FSAPT0/junccpvdz procedure for phenol dimer from the S22 database. 

mtd/basis syntax examples 

ROHFCCSD(T) ccpVDZ energy for the \(^2\Sigma^+\) state of the CN radical, with Zmatrix input. 

DCT calculation for the triplet O2 using ODC06 and ODC12 functionals. Only simultaneous algorithm is tested. 

631G H2O Test FCI Energy Point 

UHF Dipole Polarizability Test 

Various constrained energy minimizations of HOOH with ccpvdz RHF. For “fixed” coordinates, the final value is provided by the user. 

UHFCCSD(T)/ccpVDZ \(^{3}B_1\) CH2 geometry optimization via analytic gradients 

A very quick correctness test of FSAPT (see fsapt1 for a real example) 

Benzene vertical singlettriplet energy difference computation, using the PubChem database to obtain the initial geometry, which is optimized at the HF/STO3G level, before computing single point energies at the RHF, UHF and ROHF levels of theory. 

SCF ccpVDZ geometry optimzation, with Zmatrix input 

Scan fractional occupation of electrons updated values due to new BraggSlater radii 

Convergence of manybody gradients of different BSSE schemes 

Extrapolated water energies 

External potential calculation with one Ghost atom and one point charge at the same position. 

SAPT0 with S^inf exchdisp20 

Extrapolated energies with delta correction 

DFT Functional Test all values update for new BraggSlater radii 

Lithium test for coverage 

Triple and Singlet Oxygen energy SOSCF, also tests nonsymmetric density matrices 

updated dldf reference to new BraggSlater radii Dispersionless density functional (dlDF+D) internal match to Psi4 Extensive testing has been done to match supplemental info of Szalewicz et. al., Phys. Rev. Lett., 103, 263201 (2009) and Szalewicz et. al., J. Phys. Chem. Lett., 1, 550555 (2010) 

He Dimer VV10 functional test. notes: DFT_VV10_B/C overwrites the NL_DISPERSION_PARAMETERS tuple updated ‘bench’ reference values for new BraggSlater radii. 

This test case shows an example of running and analyzing a standard FSAPT0/junccpvdz procedure for phenol dimer from the S22 database. 

DFCCSD ccpVDZ gradients for the H2O molecule. 

Numpy interface testing 

Sample HF/ccpVDZ H2O computation 

wB97XD test for a large UKS molecule update ref gradient due to new BraggSlater radii 

Test case for Binding Energy of C4H5N (Pyrrole) with CO2 using MP2/def2TZVPP 

Tests OMP2 gradient in the presence of a dipole field 

CCSD/sto3g optical rotation calculation (both gauges) at two frequencies on methyloxirane 

Test case for some of the PSI4 outofcore codes. The code is given only 2.0 MB of memory, which is insufficient to hold either the A1 or B2 blocks of an ovvv quantity incore, but is sufficient to hold at least two copies of an oovv quantity incore. 

OMP3 ccpCVDZ energy with B3LYP initial guess for the NO radical 

sapt0 of charged system in ECP basis set 

Restricted DFDCT ODC12 energies with linearly dependent basis functions 

SAPT2+3(CCD) augccpVDZ+midbond computation of the water dimer interaction energy, using the augccpVDZJKFIT DF basis for SCF and augccpVDZRI for SAPT. 

wB97XD ccpVDZ gradient of S22 HCN update df/pk_ref values due to new BraggSlater radii 

Frozenfragment opt of C2h methane dimer with usercombined reference points. 

CASSCF/631G** energy point 

MBIS calculation on OH radical 

631G** H2O Test RASSCF Energy Point will default to only singles and doubles in the active space 

Multifragment opt of C2h methane dimer with usercombined reference points. 

RHF STO3G (Cartesian) and ccpVDZ (spherical) water Hessian test, against Psi3 reference values. 

CASSCF/631G** energy point 

631G** H2O Test CISD Energy Point 

OMP2.5 ccpVDZ energy for the H2O molecule. 

Test method/basis with disk_df 

RHFCC2LR/STO3G optical rotation of (S)methyloxirane. gauge = both, omega = (589 355 nm) 

Computation of VMFCcorrected water trimer gradient (geometry from J. Chem. Theory Comput. 11, 21262136 (2015)) 

reproduces dipole moments in J.F. Stanton’s “biorthogonal” JCP paper 

Finite difference optimization, run in sow/reap mode. 

Triple and Singlet Oxygen energy SOSCF, also tests nonsymmetric density matrices 

check mixing ECP and nonECP orbital/fitting basis sets in a session 

DC06 calculation for the He dimer. This performs a twostep update of the orbitals and cumulant, using DIIS extrapolation. Fourvirtual integrals are handled in the MO Basis. 

CC2(RHF)/ccpVDZ energy of H2O. 

Various DCT analytic gradients for the O2 molecule with 631G basis set 

SAPT0 augccpVDZ computation of the waterwater interaction energy, using the three SAPT codes. 

CC2(UHF)/ccpVDZ energy of H2O+. 

Analytic SVWN frequencies, compared to finite difference values 

DFMP2 frequency by difference of energies for H2O 

ccpvdz H2O Test CEPA(1) Energy 

OMP2 ccpVDZ gradient for the H2O molecule. 

CASSCF/631G** energy point 

CASSCF/631G** energy point 

Doublehybrid density functional B2PYLP. Reproduces portion of Table I in S. Grimme’s J. Chem. Phys 124 034108 (2006) paper defining the functional. 

Density fitted MP2 energy of H2, using density fitted reference and automatic looping over ccpVDZ and ccpVTZ basis sets. Results are tabulated using the built in table functions by using the default options and by specifiying the format. 

test scf castup with custom basis sets 

Single point gradient of 12B2 state of H2O+ with EOMCCSD 

Tests all grid pruning options available and screening of small weights. Check against grid size. 

Spectroscopic constants of H2, and the full ci ccpVTZ level of theory 

MBIS calculation on NaCl 

MP2 ccpVDZ gradient for the H2O molecule. 

File retention, docc, socc, and bond distances specified explicitly. 

OMP2 ccpVDZ energy for the NO molecule. 

Symmetry tests for a range of molecules. This doesn’t actually compute any energies, but serves as an example of the many ways to specify geometries in Psi4. 

MP2 ccpVDZ gradient for the NO radical 

RHFCCSD 631G** allelectron optimization of the H2O molecule 

UHFCCSD(T) ccpVDZ frozencore energy for the \(^2\Sigma^+\) state of the CN radical, with Zmatrix input. 

OMP2 ccpVDZ energy for the H2O molecule. 

RHFCCSDLR/ccpVDZ static polarizability of HOF 

SCF with various combinations of pk/densityfitting, castup/nocastup, and spherical/cartesian settings. Demonstrates that puream setting is getting set by orbital basis for all df/castup parts of calc. Demonstrates that answer doesn’t depend on presence/absence of castup. Demonstrates (by comparison to castup3) that output file doesn’t depend on options (scf_type) being set global or local. This input uses global. 

631G** H2O Test CISD Energy Point 

Extrapolated water energies 

SCF level shift on a CUHF computation 

OMP2 ccpVDZ energy for the H2O molecule. 

BHH2+ FCI/ccpVDZ Transition Dipole Moment 

Patch of a glycine with a methyl group, to make alanine, then DFSCF energy calculation with the ccpVDZ basis set 

631G MP2 transitionstate optimization with initial, computed Hessian. 

Various gradients for a strained helium dimer and water molecule 

RHF 631G** energy of water, using the MCSCF module and Zmatrix input. 

A rangeseperated gradient for SO2 to test disk algorithms by explicitly setting low memory 

test roundtripness of dict repr for psi4.core.Molecule and qcdb.Molecule 

SCF STO3G finitedifference tests 

LCCD ccpVDZ gradient for the NO radical 

Test G2 method for H2O 

DFOMP2 ccpVDZ gradients for the H2O molecule. 

ROHFCCSD ccpVDZ frozencore energy for the \(^2\Sigma^+\) state of the CN radical, with Cartesian input. 

SCF level shift on an ROHF computation 

This checks that all energy methods can run with a minimal input and set symmetry. 

Test of SFX2C1e on Water uncontracted ccpVDZ The reference numbers are from Lan Cheng’s implementation in Cfour 

Carbon/UHF FractionallyOccupied SCF Test Case 

SAPT0 augccpVDZ computation of the benzenemethane interaction energy, using the augpVDZJKFIT DF basis for SCF, the augccpVDZRI DF basis for SAPT0 induction and dispersion, and the augpVDZJKFIT DF basis for SAPT0 electrostatics and induction. This example uses frozen core as well as asyncronous I/O while forming the DF integrals and CPHF coefficients. 

Multilevel computation of water trimer energy (geometry from J. Chem. Theory Comput. 11, 21262136 (2015)) 

WaterArgon complex with ECP present; check of RHF Hessian 

apply linear fragmentation algorithm to a water cluster 

SCF level shift on an RKS computation 

631G H2O Test for coverage 

DFCCSD(AT) ccpVDZ energy for the H2O molecule. 

631G** H2O CCSD optimization by energies, with ZMatrix input 

SOSOMP2 ccpVDZ geometry optimization for the H2O molecule. 

Tests SAPT0D corrections, with a variety of damping functions/parameters 

An example of using BLAS and LAPACK calls directly from the Psi input file, demonstrating matrix multiplication, eigendecomposition, Cholesky decomposition and LU decomposition. These operations are performed on vectors and matrices provided from the Psi library. 

A general test of the MintsHelper function 

ROHFCCSD ccpVDZ energy for the \(^2\Sigma^+\) state of the CN radical 

OLCCD ccpVDZ energy with ROHF initial guess for the NO radical 

Finite difference of energies frequency, run in sow/reap mode. 

DFMP2 ccpVDZ frozen core gradient of benzene, computed at the DFSCF ccpVDZ geometry 

ccpvdz H2O Test ACPF Energy/Properties 

RHFCCSD/ccpVDZ energy of H2O partitioned into pair energy contributions. 

Patch of a glycine with a methyl group, to make alanine, then DFSCF energy calculation with the ccpVDZ basis set 

MkMRCCSD single point. \(^3 \Sigma ^\) O2 state described using the Ms = 0 component of the triplet. Uses ROHF triplet orbitals. 

RHF Density Matrix basedIntegral Screening Test for water 

Test fnocc with linear dependencies 

SAPT0 augccpVTZ computation of the charge transfer energy of the water dimer. 

FSAPT with external charge on trimer 

This test case shows an example of running and analyzing an FISAPT0/junccpvdz computation for 2,4pentanediol (targeting the intramolecular hydrogen bond between the two hydroxyl groups) 

A test of the basis specification. A benzene atom is defined using a ZMatrix containing dummy atoms and various basis sets are assigned to different atoms. The symmetry of the molecule is automatically lowered to account for the different basis sets. 

OLCCD ccpVDZ gradient for the H2O molecule. 

SCF level shift on a UHF computation 

This checks that all energy methods can run with a minimal input and set symmetry. 

OMP3 ccpCVDZ energy with ROHF initial guess for the NO radical 