xnn.common.models.charge_solve.coulomb_matrix#

xnn.common.models.charge_solve.coulomb_matrix(ewald, pos, cell=None)[source]#

gamma with E_lr(q) = 1/2 q^T gamma q for one structure (coulomb_matrix() of ewald).

Parameters:

ewald (EwaldSummation) – The kernel (sigma, dl, remove_self_interaction); exponent must be 1.
pos (Tensor) – Positions (n, 3) in Angstrom.
cell (Tensor or None) – Row-vector cell (3, 3) for a periodic structure.

Returns:

(n, n), symmetric positive definite.

Return type:

Tensor