Comparison of Methods for Point-Charge Representation of Electrostatic Fields.

摘要

The calculation of the electrostatic potential resultign form an infinite or extended array of charges in the interior of a region of interest is frequent task in computational chemistry.In case of a periodic potential this can,for example,be done by Ewald summation or by multipole methods.An important alternative are those methods where arrays of auxiliary point charges are optimized with respect to charge and/or position to reporduce the original electrostatic potential.In the literature differen tvariations are reported.we compare the performance of some of these with respect to their ability to reproduce the orginal potential and the computational effort required.Between(1)surface charges determined by the conductor-boundary condition,(2) optimized surface charges,and (3) surface charges floating on the surface we find that (2) offers good quality with small computational costs involved.