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calc_o2_matrix_element

qsym2::target::noci::backend::nonortho

Function calc_o2_matrix_element 

Source 
pub fn calc_o2_matrix_element<'a, 'b, T, SC, F>(
    lowdin_paired_coefficientss: &[LowdinPairedCoefficients<T>],
    o2_opt: Option<&'b ArrayView4<'a, T>>,
    get_jk_opt: Option<&F>,
    structure_constraint: &SC,
) -> Result<T, Error>
where
    T: ComplexFloat + ScalarOperand + Product + Display,
    SC: StructureConstraint,
    F: Fn(&Array2<T>) -> Result<(Array2<T>, Array2<T>), Error>,
    'a: 'b,
Expand description

Calculates the matrix element of a two-particle operator between two Löwdin-paired determinants.

§Arguments

  • lowdin_paired_coefficientss - A sequence of pairs of Löwdin-paired coefficients, one for each subspace determined by the specified structure constraint.
  • o2_opt - The two-particle operator in the atomic-orbital basis in physicists’ ordering.
  • get_jk_opt - The optional function callable on a density matrix $\mathbf{D}$ to calculate the corresponding $\mathbf{J}$ and $\mathbf{K}$ matrices by contracting with appropriate two-electron integrals calculated on-the-fly. Either this or o2_opt must be specified, but not both.
  • structure_constraint - The structure constraint governing the coefficients.

§Returns

The two-particle matrix element.