vibeqc.build_pair_natural_orbitals

vibeqc.build_pair_natural_orbitals(pair_amplitudes, virtual_coefficients, *, diagonal_pair, occupation_threshold, fock=None, minimum_rank=1, negative_occupation_tolerance=1e-10)

Diagonalize the Hermitian MP2 model pair density.

A zero threshold retains the complete supplied virtual space, including exactly zero-occupation directions, and is therefore the algebraic no-truncation limit. Positive thresholds retain occupations strictly larger than the threshold, subject to minimum_rank.

Parameters:

• pair_amplitudes (ndarray)

• virtual_coefficients (ndarray)

• diagonal_pair (bool)

• occupation_threshold (float)

• fock (ndarray | None)

• minimum_rank (int)

• negative_occupation_tolerance (float)

Return type:

AICCM2026DevBPNOSpace