  The evaluation of Coulomb forces is a difficult task. The summations that are
involved converge only conditionally and care has to be taken in selecting the
appropriate procedure to define the limits. The Ewald method is a standard
method for obtaining Coulomb forces, but this method is rather slow, since it
depends on the square of the number of atoms in a unit cell. In this paper we
have adapted the plane-wise summation method for the evaluation of Coulomb
forces. The use of this method allows for larger computational cells in
molecular dynamics calculations.
