quemb.shared.helper.symmetric_different_size

quemb.shared.helper.symmetric_different_size(m, n)

Return the number of unique elements in a symmetric matrix of different row and column length

This is for example the situation for pairs \(\mu, i\) where \(\mu\) is an AO and \(i\) is a fragment orbital.

The assumed structure of the symmetric matrix is:

*   *   *   *
*   *   *   *
*   *   0   0
*   *   0   0

where the stars denote non-zero elements.

Parameters:

• m (TypeVar(_T_Integral, bound= int | integer))

• n (TypeVar(_T_Integral, bound= int | integer))

Return type:

TypeVar(_T_Integral, bound= int | integer)