OPTIMIZATION OF THE EWALD SUM FOR LARGE SYSTEMS

Techniques are described for optimising the Ewald sum in the simulatio n of systems containing large numbers of charged particles. Expression s are given for the best choice of parameters to maximise performance for a specified accuracy. The algorithm for the real-space sum uses a ''small-cell'' version of the link-cell method. Various other computat ional details are discussed. In the simulation of real systems there i s considerable scope for speeding the calculation by reducing cutoffs, without loss of accuracy.