CIWavefunction

class psi4.core.CIWavefunction

Bases: psi4.core.Wavefunction

docstring

Methods Summary

Ca(self)	Returns the Alpha Orbitals.
Ca_subset(self, arg0, arg1)	Returns the requested Alpha orbital subset.
Cb(self)	Returns the Beta Orbitals.
Cb_subset(self, arg0, arg1)	Returns the requested Beta orbital subset.
D_vector(self)	docstring
Da(self)	Returns the Alpha Density Matrix.
Da_subset(self, arg0)	Returns the requested Alpha Density subset.
Db(self)	Returns the Beta Density Matrix.
Db_subset(self, arg0)	Returns the requested Beta Density subset.
Fa(self)	Returns the Alpha Fock Matrix.
Fa_subset(self, arg0)	Returns the Alpha Fock Matrix in the requested basis (AO,SO).
Fb(self)	Returns the Beta Fock Matrix.
Fb_subset(self, arg0)	Returns the Beta Fock Matrix in the requested basis (AO,SO).
H(self)	Returns the ‘Core’ Matrix (Potential + Kinetic) Integrals.
Hd_vector(self, arg0)	docstring
PCM_enabled(self)	Whether running a PCM calculation
S(self)	Returns the One-electron Overlap Matrix.
X()
alpha_orbital_space(self, id, basis, subset)	Creates OrbitalSpace with information about the requested alpha orbital space.
aotoso(self)	Returns the Atomic Orbital to Symmetry Orbital transformer.
array_variable(self, arg0)	Returns copy of the requested (case-insensitive) Matrix QC variable.
array_variables(self)	Returns the dictionary of all Matrix QC variables.
arrays()	Deprecated since version 1.4.
atomic_point_charges(self)	Returns the set atomic point charges.
basis_projection(self, arg0, arg1, arg2, arg3)	Projects a orbital matrix from one basis to another.
basisset(self)	Returns the current orbital basis.
beta_orbital_space(self, arg0, arg1, arg2)	docstring
build(mol[, basis])
c1_deep_copy(self, basis)	Returns a new wavefunction with internal data converted to \(C_1\) symmetry, using pre-c1-constructed basis
ci_nat_orbs(self)	docstring
cleanup_ci(self)	docstring
cleanup_dpd(self)	docstring
compute_energy(self)	Computes the energy of the Wavefunction.
compute_gradient(self)	Computes the gradient of the Wavefunction
compute_hessian(self)	Computes the Hessian of the Wavefunction.
compute_state_transfer(self, arg0, arg1, …)	docstring
deep_copy(self, arg0)	Deep copies the internal data.
del_array_variable(self, arg0)	Removes the requested (case-insensitive) Matrix QC variable.
del_potential_variable(self, arg0)	Removes the requested (case-insensitive) ExternalPotential QC variable.
del_scalar_variable(self, arg0)	Removes the requested (case-insensitive) double QC variable.
del_variable(key)	Removes scalar or array QCVariable key from cls if present.
density_fitted(self)	Returns whether this wavefunction was obtained using density fitting or not.
diag_h(self, arg0, arg1)	docstring
doccpi(self)	Returns the number of doubly occupied orbitals per irrep.
efzc(self)	Returns the frozen-core energy
energy(self)	Returns the Wavefunction’s energy.
epsilon_a(self)	Returns the Alpha Eigenvalues.
epsilon_a_subset(self, arg0, arg1)	Returns the requested Alpha Eigenvalues subset.
epsilon_b(self)	Returns the Beta Eigenvalues.
epsilon_b_subset(self, arg0, arg1)	Returns the requested Beta Eigenvalues subset.
esp_at_nuclei(self)	returns electrostatic potentials at nuclei
external_pot(self)	Gets the requested external potential.
force_doccpi(self, arg0)	Specialized expert use only.
force_soccpi(self, arg0)	Specialized expert use only.
form_opdm(self)	docstring
form_tpdm(self)	docstring
frequencies()
from_file(wfn_data)	Build Wavefunction from data.
frzcpi(self)	Returns the number of frozen core orbitals per irrep.
frzvpi(self)	Returns the number of frozen virtual orbitals per irrep.
get_array(key)	Deprecated since version 1.4.
get_basisset(self, arg0)	Returns the requested auxiliary basis.
get_dimension(self, arg0)	Returns the dimension of requested orbital subspace.
get_dipole_field_strength(self)	Returns a vector of length 3, containing the x, y, and z dipole field strengths.
get_opdm(self, Iroot, Jroot, spin, full_space)	Returns the one-particle density or transition matrix.
get_orbitals(self, arg0)	docstring
get_print(self)	Get the print level of the Wavefunction.
get_scratch_filename(filenumber)	Given a wavefunction and a scratch file number, canonicalizes the name so that files can be consistently written and read
get_tpdm(self, spin, symmetrize)	Returns the two-particle density matrix.
get_variable(key)	Deprecated since version 1.4.
gradient(self)	Returns the Wavefunction’s gradient.
hamiltonian(self, arg0)	docstring
has_array_variable(self, arg0)	Is the Matrix QC variable (case-insensitive) set?
has_potential_variable(self, arg0)	Is the ExternalPotential QC variable (case-insensitive) set? (This function is provisional and might be removed in the future.)
has_scalar_variable(self, arg0)	Is the double QC variable (case-insensitive) set?
has_variable(key)	Whether scalar or array QCVariable key has been set on self psi4.core.Wavefunction.
hessian(self)	Returns the Wavefunction’s Hessian.
lagrangian(self)	Returns the Lagrangian Matrix.
legacy_frequencies()	Deprecated since version 1.4.
mcscf_object(self)	docstring
mintshelper(self)	Returns the current MintsHelper object.
mo_extents(self)	returns the wavefunction’s electronic orbital extents.
module(self)	Name of the last/highest level of theory module (internal or external) touching the wavefunction.
molecule(self)	Returns the Wavefunction’s molecule.
nalpha(self)	Number of Alpha electrons.
nalphapi(self)	Returns the number of alpha orbitals per irrep.
name(self)	The level of theory this wavefunction corresponds to.
nbeta(self)	Number of Beta electrons.
nbetapi(self)	Returns the number of beta orbitals per irrep.
ndet(self)	docstring
new_civector(self, arg0, arg1, arg2, arg3)	docstring
nfrzc(self)	Number of frozen core electrons.
nirrep(self)	Number of irreps in the system.
nmo(self)	Number of molecule orbitals.
nmopi(self)	Returns the number of molecular orbitals per irrep.
no_occupations(self)	returns the natural orbital occupations on the wavefunction.
nso(self)	Number of symmetry orbitals.
nsopi(self)	Returns the number of symmetry orbitals per irrep.
opdm(self, arg0, arg1, arg2, arg3)	docstring
pitzer_to_ci_order_onel(self, arg0, arg1)	docstring
pitzer_to_ci_order_twoel(self, arg0, arg1)	docstring
potential_variable(self, key)	Returns copy of the requested (case-insensitive) ExternalPotential QC variable key.
potential_variables(self)	Returns the dictionary of all ExternalPotential QC variables.
print_vector(self, arg0, arg1)	docstring
reference_wavefunction(self)	Returns the reference wavefunction.
rotate_mcscf_integrals(self, arg0, arg1, arg2)	docstring
same_a_b_dens(self)	Returns true if the alpha and beta densities are the same.
same_a_b_orbs(self)	Returns true if the alpha and beta orbitals are the same.
scalar_variable(self, arg0)	Returns the requested (case-insensitive) double QC variable.
scalar_variables(self)	Returns the dictionary of all double QC variables.
semicanonical_orbs(self)	docstring
set_array(key, val)	Deprecated since version 1.4.
set_array_variable(self, arg0, arg1)	Sets the requested (case-insensitive) Matrix QC variable.
set_basisset(self, arg0, arg1)	Sets the requested auxiliary basis.
set_ci_guess(self, arg0)	docstring
set_energy(self, arg0)	Sets the Wavefunction’s energy.
set_external_potential(self, arg0)	Sets the requested external potential.
set_frequencies(val)	Deprecated since version 1.4.
set_gradient(self, arg0)	Sets the Wavefunction’s gradient.
set_hessian(self, arg0)	Sets the Wavefunction’s Hessian.
set_lagrangian(self, arg0)	Sets the orbital Lagrangian matrix.
set_legacy_frequencies(self, arg0)	Sets the frequencies of the Hessian.
set_module(self, module)	Sets name of the last/highest level of theory module (internal or external) touching the wavefunction.
set_name(self, arg0)	Sets the level of theory this wavefunction corresponds to.
set_orbitals(self, arg0, arg1)	docstring
set_potential_variable(self, arg0, arg1)	Sets the requested (case-insensitive) ExternalPotential QC variable.
set_print(self, arg0)	Sets the print level of the Wavefunction.
set_reference_wavefunction(self, arg0)	docstring
set_scalar_variable(self, arg0, arg1)	Sets the requested (case-insensitive) double QC variable.
set_variable(key, val)	Sets scalar or array QCVariable key to val on cls.
shallow_copy(self, arg0)	Copies the pointers to the internal data.
sigma(*args, **kwargs)	Overloaded function.
sobasisset(self)	Returns the symmetry orbitals basis.
soccpi(self)	Returns the number of singly occupied orbitals per irrep.
to_file([filename])	Converts a Wavefunction object to a base class
tpdm(self, arg0, arg1, arg2, arg3)	docstring
transform_ci_integrals(self)	Transforms the one- and two-electron integrals for a CI computation.
transform_mcscf_integrals(self, arg0)	docstring
variable(key)	Return copy of scalar or array QCVariable key from self psi4.core.Wavefunction.
variables([include_deprecated_keys])	Return all scalar or array QCVariables from cls.
write_molden([filename, do_virtual, use_natural])	Function to write wavefunction information in wfn to filename in molden format.
write_nbo(name)

Methods Documentation

Ca(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the Alpha Orbitals.

Ca_subset(self: psi4.core.Wavefunction, arg0: str, arg1: str) → psi4.core.Matrix

Returns the requested Alpha orbital subset.

Parameters

• basis (str) – {‘SO’, AO’} Should the subset be of symmetry orbitals or atomic orbitals?

• subset (str) – {‘ALL’, ‘ACTIVE’, ‘FROZEN’, ‘OCC’, ‘VIR’, ‘FROZEN_OCC’, ‘ACTIVE_OCC’, ‘ACTIVE_VIR’, ‘FROZEN_VIR’} Which subspace of orbitals should be returned?

Returns

A Pitzer-ordered matrix of the orbitals, (# basis functions, # orbitals in the subset). Pitzer-ordering is with respect to c1 symmetry if basis is AO.

Return type

Matrix

Cb(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the Beta Orbitals.

Cb_subset(self: psi4.core.Wavefunction, arg0: str, arg1: str) → psi4.core.Matrix

Returns the requested Beta orbital subset.

Parameters

• basis (str) – {‘SO’, ‘AO’} Should the subset be of symmetry orbitals or atomic orbitals?

• subset (str) – {‘ALL’, ‘ACTIVE’, ‘FROZEN’, ‘OCC’, ‘VIR’, ‘FROZEN_OCC’, ‘ACTIVE_OCC’, ‘ACTIVE_VIR’, ‘FROZEN_VIR’} Which subspace of orbitals should be returned?

Returns

A Pitzer-ordered matrix of the orbitals, (# basis functions, # orbitals in the subset). Pitzer-ordering is with respect to c1 symmetry if basis is AO.

Return type

Matrix

D_vector(self: psi4.core.CIWavefunction) → psi4.core.CIVector

docstring

Da(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the Alpha Density Matrix.

Da_subset(self: psi4.core.Wavefunction, arg0: str) → psi4.core.Matrix

Returns the requested Alpha Density subset.

Db(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the Beta Density Matrix.

Db_subset(self: psi4.core.Wavefunction, arg0: str) → psi4.core.Matrix

Returns the requested Beta Density subset.

Fa(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the Alpha Fock Matrix.

Fa_subset(self: psi4.core.Wavefunction, arg0: str) → psi4.core.Matrix

Returns the Alpha Fock Matrix in the requested basis (AO,SO).

Fb(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the Beta Fock Matrix.

Fb_subset(self: psi4.core.Wavefunction, arg0: str) → psi4.core.Matrix

Returns the Beta Fock Matrix in the requested basis (AO,SO).

H(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the ‘Core’ Matrix (Potential + Kinetic) Integrals.

Hd_vector(self: psi4.core.CIWavefunction, arg0: int) → psi4.core.CIVector

docstring

PCM_enabled(self: psi4.core.Wavefunction) → bool

Whether running a PCM calculation

S(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the One-electron Overlap Matrix.

X()

alpha_orbital_space(self: psi4.core.Wavefunction, id: str, basis: str, subset: str) → psi4.core.OrbitalSpace

Creates OrbitalSpace with information about the requested alpha orbital space.

Parameters

• id – Unique name for the orbital space.

• basis – {‘SO’, ‘AO’} Should the subspace be of symmetry orbitals or atomic orbitals?

• subset – {ALL, ACTIVE, FROZEN, OCC, VIR, FROZEN_OCC, ACTIVE_OCC, ACTIVE_VIR, FROZEN_VIR} Which subspace of orbitals should be returned?

Returns

Information on subset alpha orbitals.

Return type

OrbitalSpace

aotoso(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the Atomic Orbital to Symmetry Orbital transformer.

array_variable(self: psi4.core.Wavefunction, arg0: str) → psi4.core.Matrix

Returns copy of the requested (case-insensitive) Matrix QC variable.

array_variables(self: psi4.core.Wavefunction) → Dict[str, psi4.core.Matrix]

Returns the dictionary of all Matrix QC variables.

arrays()

Deprecated since version 1.4: Use psi4.core.Wavefunction.variables() instead.

atomic_point_charges(self: psi4.core.Wavefunction) → psi4.core.Vector

Returns the set atomic point charges.

basis_projection(self: psi4.core.Wavefunction, arg0: psi4.core.Matrix, arg1: psi4.core.Dimension, arg2: psi4.core.BasisSet, arg3: psi4.core.BasisSet) → psi4.core.Matrix

Projects a orbital matrix from one basis to another.

basisset(self: psi4.core.Wavefunction) → psi4.core.BasisSet

Returns the current orbital basis.

beta_orbital_space(self: psi4.core.Wavefunction, arg0: str, arg1: str, arg2: str) → psi4.core.OrbitalSpace

docstring

static build(mol, basis=None)

c1_deep_copy(self: psi4.core.Wavefunction, basis: psi4.core.BasisSet) → psi4.core.Wavefunction

Returns a new wavefunction with internal data converted to \(C_1\) symmetry, using pre-c1-constructed basis

ci_nat_orbs(self: psi4.core.CIWavefunction) → None

docstring

cleanup_ci(self: psi4.core.CIWavefunction) → None

docstring

cleanup_dpd(self: psi4.core.CIWavefunction) → None

docstring

compute_energy(self: psi4.core.Wavefunction) → float

Computes the energy of the Wavefunction.

compute_gradient(self: psi4.core.Wavefunction) → psi4.core.Matrix

Computes the gradient of the Wavefunction

compute_hessian(self: psi4.core.Wavefunction) → psi4.core.Matrix

Computes the Hessian of the Wavefunction.

compute_state_transfer(self: psi4.core.CIWavefunction, arg0: psi4.core.CIVector, arg1: int, arg2: psi4.core.Matrix, arg3: psi4.core.CIVector) → None

docstring

deep_copy(self: psi4.core.Wavefunction, arg0: psi4.core.Wavefunction) → None

Deep copies the internal data.

del_array_variable(self: psi4.core.Wavefunction, arg0: str) → int

Removes the requested (case-insensitive) Matrix QC variable.

del_potential_variable(self: psi4.core.Wavefunction, arg0: str) → int

Removes the requested (case-insensitive) ExternalPotential QC variable. (This function is provisional and might be removed in the future.)

del_scalar_variable(self: psi4.core.Wavefunction, arg0: str) → int

Removes the requested (case-insensitive) double QC variable.

del_variable(key)

Removes scalar or array QCVariable key from cls if present.

Return type

None

Parameters

• cls (psi4.core.Wavefunction) –

• key (str) –

density_fitted(self: psi4.core.Wavefunction) → bool

Returns whether this wavefunction was obtained using density fitting or not.

diag_h(self: psi4.core.CIWavefunction, arg0: float, arg1: float) → int

docstring

doccpi(self: psi4.core.Wavefunction) → psi4.core.Dimension

Returns the number of doubly occupied orbitals per irrep.

efzc(self: psi4.core.Wavefunction) → float

Returns the frozen-core energy

energy(self: psi4.core.Wavefunction) → float

Returns the Wavefunction’s energy.

epsilon_a(self: psi4.core.Wavefunction) → psi4.core.Vector

Returns the Alpha Eigenvalues.

epsilon_a_subset(self: psi4.core.Wavefunction, arg0: str, arg1: str) → psi4.core.Vector

Returns the requested Alpha Eigenvalues subset.

epsilon_b(self: psi4.core.Wavefunction) → psi4.core.Vector

Returns the Beta Eigenvalues.

epsilon_b_subset(self: psi4.core.Wavefunction, arg0: str, arg1: str) → psi4.core.Vector

Returns the requested Beta Eigenvalues subset.

esp_at_nuclei(self: psi4.core.Wavefunction) → psi4.core.Vector

returns electrostatic potentials at nuclei

external_pot(self: psi4.core.Wavefunction) → psi4.core.ExternalPotential

Gets the requested external potential.

force_doccpi(self: psi4.core.Wavefunction, arg0: psi4.core.Dimension) → None

Specialized expert use only. Sets the number of doubly occupied oribtals per irrep. Note that this results in inconsistent Wavefunction objects for SCF, so caution is advised.

force_soccpi(self: psi4.core.Wavefunction, arg0: psi4.core.Dimension) → None

Specialized expert use only. Sets the number of singly occupied oribtals per irrep. Note that this results in inconsistent Wavefunction objects for SCF, so caution is advised.

form_opdm(self: psi4.core.CIWavefunction) → None

docstring

form_tpdm(self: psi4.core.CIWavefunction) → None

docstring

frequencies()

static from_file(wfn_data)

Build Wavefunction from data.

Parameters

wfn_data (Union[str, Dict, Path]) – If a dict, use data directly. Otherwise, path-like passed to numpy.load() to read from disk.

Returns

A deserialized Wavefunction object

Return type

Wavefunction

frzcpi(self: psi4.core.Wavefunction) → psi4.core.Dimension

Returns the number of frozen core orbitals per irrep.

frzvpi(self: psi4.core.Wavefunction) → psi4.core.Dimension

Returns the number of frozen virtual orbitals per irrep.

get_array(key)

Deprecated since version 1.4: Use psi4.core.Wavefunction.variable() instead.

get_basisset(self: psi4.core.Wavefunction, arg0: str) → psi4.core.BasisSet

Returns the requested auxiliary basis.

get_dimension(self: psi4.core.CIWavefunction, arg0: str) → psi4.core.Dimension

Returns the dimension of requested orbital subspace.

Parameters

orbital_name (str) – {‘FZC’, ‘DRC’, ‘DOCC’, ‘ACT’, ‘RAS1’, ‘RAS2’, ‘RAS3’, ‘RAS4’, ‘POP’, ‘VIR’, ‘FZV’, ‘DRV’, ‘ALL’} Which subspace of orbitals should be returned?

get_dipole_field_strength(self: psi4.core.Wavefunction) → List[float[3]]

Returns a vector of length 3, containing the x, y, and z dipole field strengths.

get_opdm(self: psi4.core.CIWavefunction, Iroot: int, Jroot: int, spin: str, full_space: bool) → psi4.core.Matrix

Returns the one-particle density or transition matrix.

Parameters

• Iroot (int) – The index of the root in the bra. If Iroot and Jroot are -1, return the density matrix of root 0. Always use -1 for single-state calculations.

• Jroot (int) – The index of the root in the ket. Select -1 for the same as Iroot. Always use -1 for single-state calculations.

• spin (str) – {‘A’, ‘B’, ‘SUM’} Return the alpha density matrix, the beta density matrix, or their sum?

• full_space (bool) – Return a density matrix in the space of all orbitals (true) or the active orbitals (false)?

Returns

The selected one-particle density/transition matrix with Pitzer-ordered orbitals. Irrep h of the matrix corresponds to orbitals of irrep h. Element pq is <ψ|a^p a_q|ψ>.

Return type

Matrix

get_orbitals(self: psi4.core.CIWavefunction, arg0: str) → psi4.core.Matrix

docstring

get_print(self: psi4.core.Wavefunction) → int

Get the print level of the Wavefunction.

get_scratch_filename(filenumber)

Given a wavefunction and a scratch file number, canonicalizes the name so that files can be consistently written and read

get_tpdm(self: psi4.core.CIWavefunction, spin: str, symmetrize: bool) → psi4.core.Matrix

Returns the two-particle density matrix.

Parameters

• spin (str) – {“AA”, “AB”, “BB”, “SUM”} Which spin-block of the TPDM should be returned? SUM sums over all possible spin cases.

• symmetrize (bool) – Return a genuine TPDM element (false) or an “average” of TPDM elements that contract with the same integral (true)? Only working for SUM.

Returns

The two-particle density matrix with Pitzer-ordered orbitals, restricted to the active space. If symmetrize is false, element pqrs is <ψ|a^p a^r a_s a_q|ψ>. If symmetrize is true, element pqrs is obtained by summing over all “flips” of p/s, q/r, and multiplying by 0.5.

Return type

Matrix

get_variable(key)

Deprecated since version 1.4: Use psi4.core.Wavefunction.variable() instead.

gradient(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the Wavefunction’s gradient.

hamiltonian(self: psi4.core.CIWavefunction, arg0: int) → psi4.core.Matrix

docstring

has_array_variable(self: psi4.core.Wavefunction, arg0: str) → bool

Is the Matrix QC variable (case-insensitive) set?

has_potential_variable(self: psi4.core.Wavefunction, arg0: str) → bool

Is the ExternalPotential QC variable (case-insensitive) set? (This function is provisional and might be removed in the future.)

has_scalar_variable(self: psi4.core.Wavefunction, arg0: str) → bool

Is the double QC variable (case-insensitive) set?

has_variable(key)

Whether scalar or array QCVariable key has been set on self psi4.core.Wavefunction.

Return type

bool

Parameters

• cls (psi4.core.Wavefunction) –

• key (str) –

hessian(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the Wavefunction’s Hessian.

lagrangian(self: psi4.core.Wavefunction) → psi4.core.Matrix

Returns the Lagrangian Matrix.

legacy_frequencies()

Deprecated since version 1.4.

mcscf_object(self: psi4.core.CIWavefunction) → psi4.core.SOMCSCF

docstring

mintshelper(self: psi4.core.Wavefunction) → psi4.core.MintsHelper

Returns the current MintsHelper object.

mo_extents(self: psi4.core.Wavefunction) → List[psi4.core.Vector]

returns the wavefunction’s electronic orbital extents.

module(self: psi4.core.Wavefunction) → str

Name of the last/highest level of theory module (internal or external) touching the wavefunction.

molecule(self: psi4.core.Wavefunction) → psi4.core.Molecule

Returns the Wavefunction’s molecule.

nalpha(self: psi4.core.Wavefunction) → int

Number of Alpha electrons.

nalphapi(self: psi4.core.Wavefunction) → psi4.core.Dimension

Returns the number of alpha orbitals per irrep.

name(self: psi4.core.Wavefunction) → str

The level of theory this wavefunction corresponds to.

nbeta(self: psi4.core.Wavefunction) → int

Number of Beta electrons.

nbetapi(self: psi4.core.Wavefunction) → psi4.core.Dimension

Returns the number of beta orbitals per irrep.

ndet(self: psi4.core.CIWavefunction) → int

docstring

new_civector(self: psi4.core.CIWavefunction, arg0: int, arg1: int, arg2: bool, arg3: bool) → psi4.core.CIVector

docstring

nfrzc(self: psi4.core.Wavefunction) → int

Number of frozen core electrons.

nirrep(self: psi4.core.Wavefunction) → int

Number of irreps in the system.

nmo(self: psi4.core.Wavefunction) → int

Number of molecule orbitals.

nmopi(self: psi4.core.Wavefunction) → psi4.core.Dimension

Returns the number of molecular orbitals per irrep.

no_occupations(self: psi4.core.Wavefunction) → List[List[Tuple[float, int, int]]]

returns the natural orbital occupations on the wavefunction.

nso(self: psi4.core.Wavefunction) → int

Number of symmetry orbitals.

nsopi(self: psi4.core.Wavefunction) → psi4.core.Dimension

Returns the number of symmetry orbitals per irrep.

opdm(self: psi4.core.CIWavefunction, arg0: psi4.core.CIVector, arg1: psi4.core.CIVector, arg2: int, arg3: int) → List[psi4.core.Matrix]

docstring

pitzer_to_ci_order_onel(self: psi4.core.CIWavefunction, arg0: psi4.core.Matrix, arg1: psi4.core.Vector) → None

docstring

pitzer_to_ci_order_twoel(self: psi4.core.CIWavefunction, arg0: psi4.core.Matrix, arg1: psi4.core.Vector) → None

docstring

potential_variable(self: psi4.core.Wavefunction, key: str) → psi4.core.ExternalPotential

Returns copy of the requested (case-insensitive) ExternalPotential QC variable key. (This function is provisional and might be removed in the future.)

potential_variables(self: psi4.core.Wavefunction) → Dict[str, psi4.core.ExternalPotential]

Returns the dictionary of all ExternalPotential QC variables. (This function is provisional and might be removed in the future.)

print_vector(self: psi4.core.CIWavefunction, arg0: psi4.core.CIVector, arg1: int) → None

docstring

reference_wavefunction(self: psi4.core.Wavefunction) → psi4.core.Wavefunction

Returns the reference wavefunction.

rotate_mcscf_integrals(self: psi4.core.CIWavefunction, arg0: psi4.core.Matrix, arg1: psi4.core.Vector, arg2: psi4.core.Vector) → None

docstring

same_a_b_dens(self: psi4.core.Wavefunction) → bool

Returns true if the alpha and beta densities are the same.

same_a_b_orbs(self: psi4.core.Wavefunction) → bool

Returns true if the alpha and beta orbitals are the same.

scalar_variable(self: psi4.core.Wavefunction, arg0: str) → float

Returns the requested (case-insensitive) double QC variable.

scalar_variables(self: psi4.core.Wavefunction) → Dict[str, float]

Returns the dictionary of all double QC variables.

semicanonical_orbs(self: psi4.core.CIWavefunction) → None

docstring

set_array(key, val)

Deprecated since version 1.4: Use psi4.core.Wavefunction.set_variable() instead.

set_array_variable(self: psi4.core.Wavefunction, arg0: str, arg1: psi4.core.Matrix) → None

Sets the requested (case-insensitive) Matrix QC variable. Syncs with Wavefunction.gradient_ or hessian_ if CURRENT GRADIENT or HESSIAN.

set_basisset(self: psi4.core.Wavefunction, arg0: str, arg1: psi4.core.BasisSet) → None

Sets the requested auxiliary basis.

set_ci_guess(self: psi4.core.CIWavefunction, arg0: str) → None

docstring

set_energy(self: psi4.core.Wavefunction, arg0: float) → None

Sets the Wavefunction’s energy. Syncs with Wavefunction’s QC variable CURRENT ENERGY.

set_external_potential(self: psi4.core.Wavefunction, arg0: psi4.core.ExternalPotential) → None

Sets the requested external potential.

set_frequencies(val)

Deprecated since version 1.4.

set_gradient(self: psi4.core.Wavefunction, arg0: psi4.core.Matrix) → None

Sets the Wavefunction’s gradient. Syncs with Wavefunction’s QC variable CURRENT GRADIENT.

set_hessian(self: psi4.core.Wavefunction, arg0: psi4.core.Matrix) → None

Sets the Wavefunction’s Hessian. Syncs with Wavefunction’s QC variable CURRENT HESSIAN.

set_lagrangian(self: psi4.core.Wavefunction, arg0: psi4.core.Matrix) → None

Sets the orbital Lagrangian matrix.

set_legacy_frequencies(self: psi4.core.Wavefunction, arg0: psi4.core.Vector) → None

Sets the frequencies of the Hessian.

set_module(self: psi4.core.Wavefunction, module: str) → None

Sets name of the last/highest level of theory module (internal or external) touching the wavefunction.

set_name(self: psi4.core.Wavefunction, arg0: str) → None

Sets the level of theory this wavefunction corresponds to.

set_orbitals(self: psi4.core.CIWavefunction, arg0: str, arg1: psi4.core.Matrix) → None

docstring

set_potential_variable(self: psi4.core.Wavefunction, arg0: str, arg1: psi4.core.ExternalPotential) → None

Sets the requested (case-insensitive) ExternalPotential QC variable. (This function is provisional and might be removed in the future.)

set_print(self: psi4.core.Wavefunction, arg0: int) → None

Sets the print level of the Wavefunction.

set_reference_wavefunction(self: psi4.core.Wavefunction, arg0: psi4.core.Wavefunction) → None

docstring

set_scalar_variable(self: psi4.core.Wavefunction, arg0: str, arg1: float) → None

Sets the requested (case-insensitive) double QC variable. Syncs with Wavefunction.energy_ if CURRENT ENERGY.

set_variable(key, val)

Sets scalar or array QCVariable key to val on cls.

Return type

None

Parameters

• cls (psi4.core.Wavefunction) –

• key (str) –

• val (Union[psi4.core.Matrix, numpy.ndarray, float]) –

shallow_copy(self: psi4.core.Wavefunction, arg0: psi4.core.Wavefunction) → None

Copies the pointers to the internal data.

sigma(*args, **kwargs)

Overloaded function.

1. sigma(self: psi4.core.CIWavefunction, arg0: psi4.core.CIVector, arg1: psi4.core.CIVector, arg2: int, arg3: int) -> None

docstring

2. sigma(self: psi4.core.CIWavefunction, arg0: psi4.core.CIVector, arg1: psi4.core.CIVector, arg2: int, arg3: int, arg4: psi4.core.Vector, arg5: psi4.core.Vector) -> None

docstring

sobasisset(self: psi4.core.Wavefunction) → psi4.core.SOBasisSet

Returns the symmetry orbitals basis.

soccpi(self: psi4.core.Wavefunction) → psi4.core.Dimension

Returns the number of singly occupied orbitals per irrep.

to_file(filename=None)

Converts a Wavefunction object to a base class

Parameters

• wfn (Wavefunction) – A Wavefunction or inherited class

• filename (Optional[str]) – An optional filename to write the data to

Returns

A dictionary and NumPy representation of the Wavefunction.

Return type

dict

tpdm(self: psi4.core.CIWavefunction, arg0: psi4.core.CIVector, arg1: psi4.core.CIVector, arg2: int, arg3: int) → List[psi4.core.Matrix]

docstring

transform_ci_integrals(self: psi4.core.CIWavefunction) → None

Transforms the one- and two-electron integrals for a CI computation.

transform_mcscf_integrals(self: psi4.core.CIWavefunction, arg0: bool) → None

docstring

variable(key)

Return copy of scalar or array QCVariable key from self psi4.core.Wavefunction.

Returns

Scalar variables are returned as floats. Array variables not naturally 2D (like multipoles) are returned as numpy.ndarray of natural dimensionality. Other array variables are returned as Matrix and may have an extra dimension with symmetry information.

Return type

float or numpy.ndarray or Matrix

Parameters

• cls (psi4.core.Wavefunction) –

• key (str) –

Example

>>> g, wfn = psi4.gradient("hf/cc-pvdz", return_wfn=True)
>>> wfn.variable("CURRENT ENERGY")
-100.00985995185668
>>> wfn.variable("CURRENT DIPOLE")
array([ 0.        ,  0.        , -0.83217802])
>>> wfn.variable("CURRENT GRADIENT")
<psi4.core.Matrix object at 0x12d884fc0>
>>> wfn.variable("CURRENT GRADIENT").np
array([[ 6.16297582e-33,  6.16297582e-33, -9.41037138e-02],
       [-6.16297582e-33, -6.16297582e-33,  9.41037138e-02]])

variables(include_deprecated_keys=False)

Return all scalar or array QCVariables from cls.

Return type

Dict[str, Union[float, Matrix, ndarray]]

Parameters

include_deprecated_keys (bool) –

write_molden(filename=None, do_virtual=None, use_natural=False)

Function to write wavefunction information in wfn to filename in molden format. Will write natural orbitals from density (MO basis) if supplied. Warning! Most post-SCF Wavefunctions do not build the density as this is often much more costly than the energy. In addition, the Wavefunction density attributes (Da and Db) return the SO density and must be transformed to the MO basis to use with this function.

New in version 0.5: wfn parameter passed explicitly

Returns

None

Parameters

• filename (string) – destination file name for MOLDEN file (optional)

• do_virtual (bool) – do write all the MOs to the MOLDEN file (true) or discard the unoccupied MOs, not valid for NO’s (false) (optional)

• use_natural (bool) – write natural orbitals determined from density on wavefunction

Examples

1. Molden file with the Kohn-Sham orbitals of a DFT calculation.

   >>> E, wfn = energy('b3lyp', return_wfn=True)
   >>> wfn.molden('mycalc.molden')
   

2. Molden file with the natural orbitals of a CCSD computation. For correlated methods, an energy call will not compute the density. “properties” or “gradient” must be called.

   >>> E, wfn = properties('ccsd', return_wfn=True)
   >>> wfn.molden('ccsd_no.molden', use_natural=True)
   

3. To supply a custom density matrix, manually set the Da and Db of the wavefunction. This is used, for example, to write natural orbitals coming from a root computed by a CIWavefunction computation, e.g., detci, fci, casscf.` The first two arguments of get_opdm can be set to n, n where n => 0 selects the root to write out, provided these roots were computed, see NUM_ROOTS. The third argument controls the spin ("A", "B" or "SUM") and the final boolean option determines whether inactive orbitals are included.

   >>> E, wfn = energy('detci', return_wfn=True)
   >>> wfn.Da() = wfn.get_opdm(0, 0, "A", True)
   >>> wfn.Db() = wfn.get_opdm(0, 0, "B", True)
   >>> molden(wfn, 'no_root1.molden', use_natural=True)
   

write_nbo(name)