get_overlap_ab_from_qcschema

get_overlap_ab_from_qcschema(qcschema)

Builds the alpha-beta spin orbital overlap matrix from a QCSchema instance.

Parameters:

qcschema (QCSchema) – the QCSchema object from which to build the problem.

Raises:

AttributeError – when the overlap or MO coefficients are missing.

Returns:

The overlap matrix as a 2-dimensional numpy array or None if the overlap is equal to the identity matrix.

Return type:

np.ndarray | None