Electrostatic energy calculations by a Finite‐difference method: Rapid calculation of charge–solvent interaction energies

Finite‐difference Poisson–Boltzmann (FDPB) methods allow a fast and accurate calculations of the reaction field (charge–solvent) energies for molecular systems. Unfortunately, the energy in the FDPB calculations includes the self‐energies and the finite‐difference approximation to the Coulombic energies as well as the reaction field energy. A second finite‐difference calculation, in a uniform dielectric, is therefore necesssary to eliminate these contributions. In this article we describe a rapid and accurate method to calculate the self energy and finite‐difference Coulombic energies in a uniform dielectric thus eliminating the need for a second finite‐difference calculation. The computational savings for this method range from a factor of 4 for a typical protein to a factor of 103 for small molecules. © 1992 by John Wiley & Sons, Inc.