qsym2::target::noci::backend::denmat

Function calc_weighted_codensity_matrix

Source 
pub fn calc_weighted_codensity_matrix<T>(
    lowdin_paired_coefficients: &LowdinPairedCoefficients<T>,
) -> Result<Array2<T>, Error>
where
    T: ComplexFloat + ScalarOperand,
Expand description

Calculates the weighted codensity matrix between a set of Löwdin-paired spin-orbitals in determinants $^{w}\Psi$ and $^{x}\Psi$.

The weighted codensity matrix described above is given by

    ^{wx}\mathbf{W} =
        \sum_{\substack{i = 1\\ ^{wx}\lambda_i \neq 0}}^{N_{\mathrm{e}}}
            \frac{^{wx}\mathbf{P}_i}{^{wx}\lambda_i}

where $^{wx}\mathbf{P}_i$ is the unweighted codensity matrix between Löwdin-paired spin-orbitals $i$ in determinants $^{w}\Psi$ and $^{x}\Psi$, and the sum runs over up to :math:N_{\mathrm{e}} pairs of Löwdin-paired spin-orbitals of consideration, excluding those that have zero Löwdin overlaps.

§Arguments

  • lowdin_paired_coefficients - Structure containing the Löwdin-paired coefficient matrices.

§Returns

The weighted codensity matrix $^{wx}\mathbf{W}$.