Convergence of lattice sums in hartree‐fock LCAO calculations

It is shown that in evaluating the elements of the Fock matrix for the case of translational symmetry fast convergence can be achieved using a Gaussian‐lobe basis. The summation over the next‐neighbour shell should be sufficient for many applications. It is pointed out that the separation in volume‐dependent and structure‐dependent terms is not unique.