qsym2

Functions

project_slater_determinant

Python

project_slater_determinant(
    inp_sym: str,
    pydet: PySlaterDeterminant,
    projection_targets: Sequence[str | int],
    density_matrix_calculation_thresholds: tuple[float, float] | None,
    pybaos: Sequence[PyBasisAngularOrder],
    use_magnetic_group: MagneticSymmetryAnalysisKind | None,
    use_double_group: bool,
    symmetry_transformation_kind: SymmetryTransformationKind,
    write_character_table: bool = True,
    infinite_order_to_finite: int | None = None,
    sao: Py2DArray_f64 | Py2DArray_c128 | None = None,
    sao_h: Py2DArray_f64 | Py2DArray_c128 | None = None,
) -> tuple[list[str], PyMultiDeterminants]

Python-exposed function to perform symmetry projection for real and complex Slater determinants.

Parameters:

• inp_sym

  (str) –

  A path to the QSym2FileType::Sym file containing the symmetry-group detection result for the system. This will be used to construct abstract groups and character tables for symmetry projection.

• pydet

  (PySlaterDeterminant) –

  A Slater determinant whose coefficient matrices are of type float64 or complex128.

• projection_targets

  (Sequence[str | int]) –

  A sequence of subspace labels for projection. Each label is either a symbolic string or a numerical index for the subspace in the character table of the prevailing group.

• density_matrix_calculation_thresholds

  (tuple[float, float] | None) –

  An optional pair of thresholds for Löwdin pairing, one for checking zero off-diagonal values, one for checking zero overlaps, when computing multi-determinantal density matrices. If None, no density matrices will be computed.

• pybaos

  (Sequence[PyBasisAngularOrder]) –

  Python-exposed structures containing basis angular order information, one for each explicit component per coefficient matrix.

• use_magnetic_group

  (MagneticSymmetryAnalysisKind | None) –

  An option indicating if the magnetic group is to be used for symmetry analysis, and if so, whether unitary representations or unitary-antiunitary corepresentations should be used.

• use_double_group

  (bool) –

  A boolean indicating if the double group of the prevailing symmetry group is to be used for representation analysis instead.

• symmetry_transformation_kind

  (SymmetryTransformationKind) –

  An enumerated type indicating the type of symmetry transformations to be performed on the origin electron density to generate the orbit.

• write_character_table

  (bool, default: True ) –

  A boolean indicating if the character table of the prevailing symmetry group is to be printed out.

• infinite_order_to_finite

  (int | None, default: None ) –

  The finite order with which infinite-order generators are to be interpreted to form a finite subgroup of the prevailing infinite group. This finite subgroup will be used for symmetry analysis.

• sao

  (Py2DArray_f64 | Py2DArray_c128 | None, default: None ) –

  The optional atomic-orbital overlap matrix whose elements are of type float64 or complex128. If this is not present, no squared norms of the resulting multi-determinants will be computed.

• sao_h

  (Py2DArray_f64 | Py2DArray_c128 | None, default: None ) –

  The optional complex-symmetric atomic-orbital overlap matrix whose elements are of type float64 or complex128. This is required if antiunitary symmetry operations are involved.

Returns:

• tuple[list[str], PyMultiDeterminants] –

  The result will be returned as a tuple where the first item is a list of the labels of the subspaces used for projection, and the second item is an object containing the Slater determinant basis and the linear combination coefficients as a two-dimensional array with each column corresponding to one projected state.