


LRI_OVERLAP_MATRIX {Keyword} 

Specifies whether to calculate the inverse or the pseudoinverse of the overlap matrix
of the auxiliary basis set. Calculating the pseudoinverse is necessary for very large
auxiliary basis sets, but more expensive. Using the pseudoinverse, consistent forces
are not guaranteed yet. 

This keyword cannot be repeated
and it expects
precisely one keyword.


Default value:
INVERSE 

List of valid keywords:

 AUTOSELECT
 Choose automatically for each pair whether to calculate the inverse or pseudoinverse
based on the condition number of the overlap matrix for each pair. Calculating the
pseudoinverse is much more expensive.

 INVERSE
 Calculate inverse of the overlap matrix.

 PSEUDO_INVERSE_DIAG
 Calculate the pseudoinverse of the overlap matrix by prior diagonalization.

 PSEUDO_INVERSE_SVD
 Calculate the pseuodinverse of the overlap matrix using singular value decomposition.
