# PSI4 API: Linking C++ and Python¶

## psi4.core Module¶

C++ Innards of Psi4: Open-Source Quantum Chemistry

### Functions¶

 DASUM(arg0, arg1, arg2, arg3) docstring DAXPY(arg0, arg1, arg2, arg3, arg4, arg5, arg6) docstring DCOPY(arg0, arg1, arg2, arg3, arg4, arg5) docstring DDOT(arg0, arg1, arg2, arg3, arg4, arg5) docstring DGBMV(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DGEEV(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DGEMM(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DGEMV(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DGER(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DGETRF(arg0, arg1, arg2, arg3, arg4, arg5) docstring DGETRI(arg0, arg1, arg2, arg3, arg4, arg5, arg6) docstring DGETRS(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DNRM2(arg0, arg1, arg2, arg3) docstring DPOTRF(arg0, arg1, arg2, arg3, arg4) docstring DPOTRI(arg0, arg1, arg2, arg3, arg4) docstring DPOTRS(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DROT(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DSBMV(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DSCAL(arg0, arg1, arg2, arg3, arg4) docstring DSWAP(arg0, arg1, arg2, arg3, arg4, arg5) docstring DSYEV(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DSYMM(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DSYMV(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DSYR(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DSYR2(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DSYR2K(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DSYRK(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DSYSV(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DTBMV(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DTBSV(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DTRMM(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DTRMV(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DTRSM(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring DTRSV(arg0, arg1, arg2, arg3, arg4, arg5, ...) docstring IDAMAX(arg0, arg1, arg2, arg3) docstring adc(ref_wfn) Runs the ADC propagator code, for excited states. Returns copy of the Matrix QCVariable key (case-insensitive); prefer variable() Returns dictionary of all Matrix QCVariables; prefer variables() Redirects output to /dev/null. benchmark_blas1(max_dim, min_time) Perform benchmark traverse of BLAS 1 routines. benchmark_blas2(max_dim, min_time) Perform benchmark traverse of BLAS 2 routines. benchmark_blas3(max_dim, min_time[, nthread]) Perform benchmark traverse of BLAS 3 routines. benchmark_disk(max_dim, min_time) Perform benchmark of PSIO disk performance. benchmark_integrals(max_am, min_time) Perform benchmark of psi integrals (of libmints type). benchmark_math(min_time) Perform benchmark of common double floating point operations including most of cmath. ccdensity(ref_wfn) Runs the code to compute coupled cluster density matrices. ccenergy(ref_wfn) Runs the coupled cluster energy code. cceom(ref_wfn) Runs the equation of motion coupled cluster code for excited states. cchbar(ref_wfn) Runs the code to generate the similarity transformed Hamiltonian. cclambda(ref_wfn) Runs the coupled cluster lambda equations code. ccresponse(ref_wfn) Runs the coupled cluster response theory code. cctransort(ref_wfn) Runs cctransort that transforms and reorders integrals for use in the coupled cluster codes. cctriples(ref_wfn) Runs the coupled cluster (T) energy code. Remove scratch files. Reset options to clean state. Reinitialize timers for independent timer.dat entries. Empties all double and Matrix QCVariables that have been set in global memory. Closes the output file. dct(ref_wfn) Runs the density cumulant (functional) theory code. Removes the Matrix QCVariable key (case-insensitive); prefer del_variable() Removes the double QCVariable key (case-insensitive); prefer del_variable() Removes scalar or array QCVariable key from global memory if present. detci(ref_wfn) Runs the determinant-based configuration interaction code. dfmp2(ref_wfn) Runs the DF-MP2 code. dfocc(ref_wfn) Runs the density-fitted orbital optimized CC codes. dlpno(arg0) Runs the DLPNO codes. dmrg(ref_wfn) Runs the CheMPS2 interface DMRG code. doublet(A, B[, transA, transB]) Returns the multiplication of two matrices A and B, with options to transpose each beforehand fcidump_tei_helper(nirrep, restricted, ...) Write integrals to file in FCIDUMP format Called upon psi4 module exit to closes timers and I/O. Flushes the output file. fnocc(ref_wfn) Runs the FNO-CCSD(T)/QCISD(T)/MP4/CEPA energy code Returns the currently active molecule object. Deprecated since version 1.4. Deprecated since version 1.4. Deprecated since version 1.4. Returns the path to shared text resources, PSIDATADIR Return keyword key value at global (all-module) scope. Returns a list of all global options. Deprecated since version 1.2. Returns the global gradient as a (nat, 3) Matrix object. Returns the currently active legacy molecule object. get_local_option(module, key) Return keyword key value at module scope. Returns the amount of memory available to Psi (in bytes). Returns the number of threads to use in SMP parallel computations. get_option(module, key) Return keyword key value used by module. Get options Returns output file name (stem + suffix, no directory). Deprecated since version 1.4. Deprecated since version 1.4. get_writer_file_prefix(molecule_name) Returns the prefix to use for writing files for external programs. Deprecated since version 1.4. Is the Matrix QCVariable key (case-insensitive) set? Prefer has_variable() Whether keyword key value has been touched at global (all-module) scope. has_local_option_changed(module, key) Whether keyword key value has been touched at module scope. has_option_changed(module, key) Whether keyword key value has been touched or is default. Is the double QCVariable key (case-insensitive) set? Prefer has_variable() Whether scalar or array QCVariable key has been set in global memory. Called upon psi4 module import to initialize timers, singletons, and I/O. Returns the current legacy_wavefunction object from the most recent computation. mcscf(arg0) Runs the MCSCF code, (N.B. mrcc_generate_input(arg0, arg1) Generates an input for Kallay's MRCC code. mrcc_load_densities(arg0, arg1) Reads in the density matrices from Kallay's MRCC code. occ(ref_wfn) Runs the orbital optimized CC codes. Cleans up the optimizer's scratch files. option_exists_in_module(module, key) Whether keyword key is a valid keyword for module. Get dictionary of whether options of module have changed. Runs the geometry optimization code. Returns the name of the output file. plugin(arg0, arg1) Call the plugin of name arg0. plugin_close(arg0) Close the plugin of name arg0. Close all open plugins. plugin_load(arg0) Load the plugin of name arg0. Sets up the options library to return options pertaining to the module or plugin name (e.g. Prints the currently set global (all modules) options to the output file. Prints the currently set options (to the output file) for the current module. print_out(arg0) Prints a string (using sprintf-like notation) to the output file. Prints to output file all QCVariables that have been set in global memory. Returns the location of the source code. psimrcc(arg0) Runs the multireference coupled cluster code. Reopens the output file. Clear the touched status for keyword key at global (all-module) scope. revoke_local_option_changed(module, key) Clear the touched status for keyword key at module scope. run_gdma(ref_wfn, datfilename) Runs the GDMA interface code. sapt(dimer_wfn, monoa_wfn, monob_wfn) Runs the symmetry adapted perturbation theory code. Returns the double QCVariable key (case-insensitive); prefer variable() Returns dictionary of all double QCVariables; prefer variables() scatter(arg0, arg1, arg2, arg3, arg4) New Scatter function. scfgrad(ref_wfn) Run scfgrad, which is a specialized DF-SCF gradient program. scfhess(ref_wfn) Run scfhess, which is a specialized DF-SCF hessian program. set_active_molecule(molecule) Activates a previously defined molecule in global memory so next computations use it. set_array_variable(key, value) Sets the requested (case-insensitive) Matrix QCVariable; prefer set_variable() set_datadir(psidatadir) Sets the path to shared text resources, PSIDATADIR. set_global_option(*args, **kwargs) Overloaded function. set_global_option_python(key, EXTERN) This is a fairly hacky way to get around EXTERN issues. Deprecated since version 1.2. Assigns the global gradient to the values in the (nat, 3) Matrix argument. set_legacy_molecule(molecule) Activates a previously defined molecule in global memory so next computations use it. Sets the current legacy_wavefunction object from the most recent computation. set_local_option(*args, **kwargs) Overloaded function. set_local_option_python(key, value) Sets value to Python keyword key scoped only to a single module. set_memory_bytes(memory[, quiet]) Sets the memory available to Psi (in bytes); prefer psi4.driver.set_memory(). set_num_threads(nthread[, quiet]) Sets the number of threads to use in SMP parallel computations. set_output_file(*args, **kwargs) Overloaded function. Deprecated since version 1.4. set_scalar_variable(key, value) Sets the double QCVariable key (case-insensitive); prefer set_variable() set_variable(key, val) Sets scalar or array QCVariable key to val in global memory. timer_off(label) Stop timer with label. timer_on(label) Start timer with label. triplet(A, B, C[, transA, transB, transC]) Returns the multiplication of three matrices, with options to transpose each beforehand. Start module-level timer. Stop module-level timer. variable(key) Return copy of scalar or array QCVariable key from global memory. variables([include_deprecated_keys]) Return all scalar or array QCVariables from global memory. Deprecated since version 1.4.

### Classes¶

 AOShellCombinationsIterator AngularMomentumInt Computes angular momentum integrals BSVec BasisExtents docstring BasisFunctions docstring BasisSet Contains basis set information BlockOPoints docstring BoysLocalizer Performs Boys orbital localization CCWavefunction Specialized Wavefunction used by the ccenergy, cceom, ccgradient, etc. CIVector docstring CIWavefunction docstring CUHF docstring CdSalc Cartesian displacement SALC CdSalcList Class for generating symmetry adapted linear combinations of Cartesian displacements CharacterTable Contains the character table of the point group CorrelationFactor docstring CorrelationTable Provides a correlation table between two point groups CubeProperties docstring DFEP2Wavefunction A density-fitted second-order Electron Propagator Wavefunction. DFHelper docstring DFJCOSK docstring DFSOMCSCF docstring DFTGrid docstring DFTensor docstring Deriv Computes gradients of wavefunctions DerivCalcType Members: DiagonalizeOrder Defines ordering of eigenvalues after diagonalization Dimension Initializes and defines Dimension Objects DipoleInt Computes dipole integrals DirectJK docstring DiskSOMCSCF docstring Dispersion docstring ERI Computes normal two electron repulsion integrals ERISieve docstring ESPPropCalc ESPPropCalc gives access to routines calculating the ESP on a grid ElectricFieldInt Computes electric field integrals ElectrostaticInt Computes electrostatic integrals ExternalPotential Stores external potential field, computes external potential matrix FCHKWriter Extracts information from a wavefunction object, and writes it to an FCHK file FDDS_Dispersion docstring FISAPT A Fragment-SAPT Wavefunction FittedSlaterCorrelationFactor docstring FittingMetric docstring FragmentType Fragment activation status Functional docstring GaussianShell Class containing information about basis functions GaussianType 0 if Cartesian, 1 if Pure GeometryUnits The units used to define the geometry HF docstring IO docstring IOManager PSIOManager is a class designed to be used as a static object to track all PSIO operations in a given PSI4 computation IntVector Class handling vectors with integer values IntegralFactory Computes integrals IntegralTransform IntegralTransform transforms one- and two-electron integrals within general spaces IrreducibleRepresentation An irreducible representation of the point group JK docstring KineticInt Computes kinetic integrals LaplaceDenominator Computer class for a Laplace factorization of the four-index energy denominator in MP2 and coupled-cluster LibXCFunctional docstring Localizer Class containing orbital localization procedures MOSpace Defines orbital spaces in which to transform integrals MOWriter Writes the MOs Matrix Class for creating and manipulating matrices MatrixFactory Creates Matrix objects MemDFJK docstring MintsHelper Computes integrals MoldenWriter Writes wavefunction information in molden format MolecularGrid docstring Molecule Class to store the elements, coordinates, fragmentation pattern, basis sets, charge, multiplicity, etc. MultipoleInt Computes arbitrary-order multipole integrals MultipoleSymmetry docstring NBOWriter The Natural Bond Orbital Writer NablaInt Computes nabla integrals OEProp docstring OneBodyAOInt Basis class for all one-electron integrals OneBodySOInt Options docstring OrbitalSpace Contains information about the orbitals OverlapInt Computes overlap integrals PMLocalizer Performs Pipek-Mezey orbital localization PetiteList Handles symmetry transformations PointFunctions docstring PointGroup Contains information about the point group PotentialInt Computes potential integrals PrimitiveType May be Normalized or Unnormalized Prop docstring PsiReturnType Return status. QuadrupoleInt Computes quadrupole integrals RHF docstring RKSFunctions docstring ROHF docstring SADGuess docstring SOBasisSet An SOBasis object describes the transformation from an atomic orbital basis to a symmetry orbital basis. SOMCSCF docstring SalcComponent Component of a Cartesian displacement SALC in the basis of atomic displacements. SaveType The layout of the matrix for saving ShellInfo Slice Slicing for Matrix and Vector objects SuperFunctional docstring SymmetryOperation Class to provide a 3 by 3 matrix representation of a symmetry operation, such as a rotation or reflection. TLaplaceDenominator Computer class for a Laplace factorization of the six-index energy denominator in coupled-cluster theory ThreeCenterOverlapInt Three center overlap integrals TracelessQuadrupoleInt Computes traceless quadrupole integrals TwoBodyAOInt Two body integral base class TwoElectronInt Computes two-electron repulsion integrals UHF docstring UKSFunctions docstring VBase docstring Vector Class for creating and manipulating vectors Vector3 Class for vectors of length three, often Cartesian coordinate vectors, and their common operations Wavefunction docstring dpdbuf4 docstring dpdfile2 docstring psio_entry docstring

## psi4.driver Package¶

### Functions¶

 activate(mol) Function to set molecule object mol as the current active molecule. banner(text[, type, width, strNotOutfile]) Format text into a banner style and print or return it. basis_helper(block[, name, key, set_option]) Helper to specify a custom basis set in PsiAPI mode. cbs(func, label, **kwargs) Function to define a multistage energy method from combinations of basis set extrapolations and delta corrections and condense the components into a minimum number of calculations. compare_fchkfiles(expected, computed, ...) Comparison function for output data in FCHK (formatted checkpoint) file format. compare_fcidumps(expected, computed, label) Comparison function for FCIDUMP files. compare_moldenfiles(expected, computed[, ...]) Comparison function for output data in Molden file format. copy_file_from_scratch(filename, prefix, ...) Move a file out of scratch following the naming convention. copy_file_to_scratch(filename, prefix, ...) Move a file into scratch following the naming convention. create_plugin(name, template) rtype: None cubeprop(wfn, **kwargs) Evaluate properties on a grid and generate cube files. Function to dynamically add extra members to the core.Molecule class. energies_from_fcidump(intdump) From integrals dictionary generated from fcidump_from_file(), compute energies. energy(name, **kwargs) Function to compute the single-point electronic energy. fchk(wfn, filename, *[, debug, strict_label]) Function to write wavefunction information in wfn to filename in Gaussian FCHK format. fcidump(wfn[, fname, oe_ints]) Save integrals to file in FCIDUMP format as defined in Comp. fcidump_from_file(fname) Function to read in a FCIDUMP file. find_approximate_string_matches(seq1, ...) Find list of approximate (within max_distance) matches to string seq1 among options. freq(name, **kwargs) Function to compute harmonic vibrational frequencies. frequencies(name, **kwargs) Function to compute harmonic vibrational frequencies. frequency(name, **kwargs) Function to compute harmonic vibrational frequencies. gdma(wfn[, datafile]) Function to use wavefunction information in wfn and, if specified, additional commands in filename to run GDMA analysis. geometry(geom[, name]) Function to create a molecule object of name name from the geometry in string geom. Return the total memory allocation in bytes. gradient(name, **kwargs) Function complementary to optimize(). hessian(name, **kwargs) Function complementary to frequency(). ipi_broker(LOT[, molecule, serverdata, options]) Runs IPIBroker to connect to i-PI (https://ipi-code.org/). levenshtein(seq1, seq2) Compute the Levenshtein distance between two strings. mdi_run(scf_method, **kwargs) Begin functioning as an MDI engine message_box(message[, max_width, min_width]) Put a message string into a box for extra attention. molden(wfn[, filename, density_a, ...]) Function to write wavefunction information in wfn to filename in molden format. molecule_get_attr(self, name) Function to redefine __getattr__ method of molecule class. molecule_set_attr(self, name, value) Function to redefine __setattr__ method of molecule class. oeprop(wfn, *args, **kwargs) Evaluate one-electron properties. opt(name, **kwargs) Function to perform a geometry optimization. optimize(name, **kwargs) Function to perform a geometry optimization. optimize_geometric(name, **kwargs) pcm_helper(block) Helper to specify the multiline PCMSolver syntax for PCM. process_input(raw_input[, print_level]) Function to preprocess raw input, the text of the input file, then parse it, validate it for format, and convert it into legitimate Python. prop(*args, **kwargs) Function to compute various properties. properties(*args, **kwargs) Function to compute various properties. sanitize_name(name) Function to return name in coded form, stripped of characters that confuse filenames, characters into lowercase, + into p, * into s, and (, ), -, & , into _. scf_helper(name[, post_scf]) Function serving as helper to SCF, choosing whether to cast up or just run SCF with a standard guess. scf_wavefunction_factory(name, ref_wfn, ...) Builds the correct (R/U/RO/CU HF/KS) wavefunction from the provided information, sets relevant auxiliary basis sets on it, and prepares any empirical dispersion. set_memory(inputval[, execute, quiet]) Reset the total memory allocation. set_module_options(module, options_dict) Sets Psi4 module options from a module specification and input dictionary. set_options(options_dict[, verbose]) Sets Psi4 options from an input dictionary. tdscf(wfn, **kwargs) vibanal_wfn(wfn[, hess, irrep, molecule, ...]) Function to perform analysis of a hessian or hessian block, specifically.

### Classes¶

 AtomicComputer Computer for analytic single-geometry computations. ConvergenceError(eqn_description, iteration) Error called for problems with converging an iterative method. EmpiricalDispersion(*[, name_hint, ...]) Lightweight unification of empirical dispersion calculation modes. ManagedMethodError(circs) Error called when a requested level of theory and derivative level are nominally available but not for the particular conditions (e.g., reference, algorithm, active orbitals, QC module, etc.) requested. Error called when requested level or theory or derivative level are not available. Error called for problems with geometry optimizer. Error called for problems parsing a text file. PastureRequiredError(option) Error called when the specified value of option requires some module(s) from Psi4Pasture, but could not be imported. PsiException Error class for PSI4. Hold charges and psi4.core.ExternalPotential. Hold charges and psi4.core.ExternalPotential. SCFConvergenceError(eqn_description, ...) Error called for problems with SCF iterations. TDSCFConvergenceError(iteration, wfn, what, ...) Error called for problems with TDSCF iterations. Error called when a compare_values() or other comparison function fails. UpgradeHelper(old, new, version, elaboration) Error called on previously valid syntax that now isn't and a simple syntax transition is possible. Input specification has problems.

## psi4.driver.p4util Package¶

Miscellaneous tools for driver and users.

### Functions¶

 Return a context manager that will collect the state (value and changed status) of a list of keywords osd that can initialize OptionsState on entry to the with-statement and restore the collected state when exiting the with-statement. all_casings(input_string) Return a generator of all lettercase permutations of input_string. array_to_matrix(self, arr[, name, dim1, dim2]) Converts a NumPy array or list of NumPy arrays into a PSI4 Matrix or Vector (irreped if list). banner(text[, type, width, strNotOutfile]) Format text into a banner style and print or return it. basis_helper(block[, name, key, set_option]) Helper to specify a custom basis set in PsiAPI mode. Convert square NumPy array to a single block diagonal array. cg_solver(rhs_vec, hx_function, preconditioner) Solves the $$Ax = b$$ linear equations via Conjugate Gradient. compare_fchkfiles(expected, computed, ...) Comparison function for output data in FCHK (formatted checkpoint) file format. compare_fcidumps(expected, computed, label) Comparison function for FCIDUMP files. compare_moldenfiles(expected, computed[, ...]) Comparison function for output data in Molden file format. copy_file_from_scratch(filename, prefix, ...) Move a file out of scratch following the naming convention. copy_file_to_scratch(filename, prefix, ...) Move a file into scratch following the naming convention. cubeprop(wfn, **kwargs) Evaluate properties on a grid and generate cube files. davidson_solver(engine, guess, *, nroot[, ...]) Solves for the lowest few eigenvalues and eigenvectors of a large problem emulated through an engine. Return a copy of collection seq without any duplicate entries. energies_from_fcidump(intdump) From integrals dictionary generated from fcidump_from_file(), compute energies. expand_psivars(pvdefs[, verbose]) From rules on building QCVariables from others, set new variables to P::e if all the contributors are available. fcidump(wfn[, fname, oe_ints]) Save integrals to file in FCIDUMP format as defined in Comp. fcidump_from_file(fname) Function to read in a FCIDUMP file. find_approximate_string_matches(seq1, ...) Find list of approximate (within max_distance) matches to string seq1 among options. format_molecule_for_input(mol[, name, forcexyz]) Function to return a string of the output of process_input() applied to the XYZ format of molecule, passed as either fragmented geometry string mol or molecule instance mol. format_options_for_input([molecule]) Function to return a string of commands to replicate the current state of user-modified options. free_atom_volumes(wfn, **kwargs) Computes free-atom volumes using MBIS density partitioning. Return the total memory allocation in bytes. get_psifile(fileno[, pidspace]) Form full path and filename for psi scratch file. getattr_ignorecase(module, attr) Extract attribute attr from module if attr is available in any possible lettercase permutation. hamiltonian_solver(engine, guess, *, nroot) Finds the smallest eigenvalues and associated right and left hand eigenvectors of a large real Hamiltonian eigenvalue problem emulated through an engine. Return a context manager that will collect the current state of Process:environment.options on entry to the with-statement and clear and restore the collected keywords state when exiting the with-statement. import_ignorecase(module) Import loader for module in any possible lettercase permutation. kwargs_lower(kwargs) Function to rebuild and return kwargs dictionary sanitized. levenshtein(seq1, seq2) Compute the Levenshtein distance between two strings. mat2arr(mat) Convert Matrix to List. message_box(message[, max_width, min_width]) Put a message string into a box for extra attention. oeprop(wfn, *args, **kwargs) Evaluate one-electron properties. pcm_helper(block) Helper to specify the multiline PCMSolver syntax for PCM. plump_qcvar(val, shape_clue[, ret]) Prepare serialized QCVariable for set_variable() by converting flat arrays into shaped ones and floating strings. Prefactor for converting microscopic observable to decadic molar extinction coefficient in electronic circular dichroism. Prefactor for converting microscopic observable to decadic molar extinction coefficient in one-photon absorption. prepare_options_for_modules([changedOnly, ...]) Capture current state of psi4.core.Options information. Collect current state of psi4.core.Options information for reloading by set_options(). provenance_stamp(routine[, module]) Prepare QCSchema Provenance with PSI4 credentials. set_memory(inputval[, execute, quiet]) Reset the total memory allocation. set_module_options(module, options_dict) Sets Psi4 module options from a module specification and input dictionary. set_options(options_dict[, verbose]) Sets Psi4 options from an input dictionary. spectrum(*, poles, residues[, kind, ...]) One-photon absorption (OPA) or electronic circular dichroism (ECD) spectra with phenomenological line broadening. state_to_atomicinput(*, driver, method[, ...]) Form a QCSchema for job input from the current state of PSI4 settings.

### Classes¶

 DIIS([max_vec, removal_policy]) An object to assist in the DIIS extrpolation procedure. Gaussian(domain, gamma) Gaussian function on domain, centered at x_0 with broadening gamma. InPsight(molecule) POV-Ray visualization. Lineshape(domain, gamma) Lineshape ABC Lorentzian(domain, gamma) Lorentzian function on domain, centered at x_0 with broadening gamma. OptionState(option[, module]) Store the state (value and changed status) of a single option. OptionsState(*largs) Store multiple OptionState() objects. Abstract Base Class defining the API required by solver engines