Efficient solution of Poisson's equation in linear combination of atomic orbitals calculations of crystal electronic structure

An accurate and efficient method has previously been described for the evaluation of electrostatic contributions in linear combination of atomic orbitals--molecular orbitals calculations. The method is based on a decomposition of the charge density into a sum of atom-centered contributions, which reproduces the near-nucleus rapid variation of the charge density to arbitrary accuracy, plus a slowly varying remainder. Here the method is extended to the electronic structure of an infinite periodic solid. It is illustrated by an evaluation of the electronic structure of a one-layer Ru(0001) sheet