# DFEP2Wavefunction

class `psi4.core.``DFEP2Wavefunction`

  Bases: `psi4.core.Wavefunction`

  A density-fitted second-order Electron Propagator Wavefunction.

  Methods Summary

  `compute`(self, arg0) | Computes the density-fitted EP2 energy for the input orbitals

  Methods Documentation

  `compute`(self: psi4.core.DFEP2Wavefunction, arg0: List[List[int]]) → List[List[Tuple[float, float]]]

    Computes the density-fitted EP2 energy for the input orbitals

  `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.

  `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.

  `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.

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

    Returns the Lagrangian Matrix.

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

    docstring

  `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`()
  `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 BasisSet basis

  `compute`(self: psi4.core.DFEP2Wavefunction, arg0: List[List[int]]) → List[List[Tuple[float, float]]]

    Computes the density-fitted EP2 energy for the input orbitals

  `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.

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

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

  `del_variable`(key)
  `density_fitted`(self: psi4.core.Wavefunction) → bool

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

  `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

  `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.

  `frequencies`()
  static `from_file`(wfn_data)

    Summary

    Parameters: | wfn_data (str or dict) – If a str reads a Wavefunction from a disk otherwise, assumes the data is passed in.
    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)
  `get_basisset`(self: psi4.core.Wavefunction, arg0: str) → psi4.core.BasisSet

    Returns the requested auxiliary basis.

  `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_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_variable`(key)
  `gradient`(self: psi4.core.Wavefunction) → psi4.core.Matrix

    Returns the Wavefunction’s gradient.

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

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

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

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

  `has_variable`(key)
  `hessian`(self: psi4.core.Wavefunction) → psi4.core.Matrix

    Returns the Wavefunction’s Hessian.

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

    returns the wavefunction’s electronic orbital extents.

  `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.

  `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.

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

    Returns the reference wavefunction.

  `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.

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

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

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

    Sets the requested auxiliary basis.

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

    Sets the Wavefunction’s energy.

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

    Sets the requested external potential.

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

    Sets the Wavefunction’s gradient.

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

    Sets the Wavefunction’s Hessian.

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

    Sets the frequencies of the Hessian.

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

    Sets the level of theory this wavefunction corresponds to.

  `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.

  `set_variable`(key, val)
  `shallow_copy`(self: psi4.core.Wavefunction, arg0: psi4.core.Wavefunction) → None

    Copies the pointers to the internal data.

  `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 (None , optional) – An optional filename to write the data to

    Returns: | A dictionary and NumPy representation of the Wavefunction.
    Return type: | dict

  `variable`(key)
  `variables`()