General Purpose Electrostatic Embedding Potential

We present a method and a computer code for accurate calculation of electrostatic potential in an arbitrary crystalline lattice modeled using a finite system. The method is based on complementing a lattice unit cell with a set of point charges in order to annihilate simultaneously all components of any number of the lowest multipole moments. The positions and the values of the complementary charges are determined analytically. The electrostatic potential produced by each modified cell is short range, and the corresponding lattice series converges absolutely, which makes it convenient to use in embedded cluster calculations of solids, surfaces, and low-dimensional structures. The method is illustrated by application to the rutile TiO(2) and a-quartz SiO(2) lattices and to those of several complex minerals.