We describe two algorithms for the parallel calculation of a CHARMm‐like force field in macromolecules. For a molecule with a given number of atoms, we show that there is an optimal number of processors leading to a minimum computation time. At the optimum, both the number of processors and the computation time are proportional to the number of atoms. © 1992 by John Wiley & Sons, Inc. Copyright © 1992 John Wiley & Sons, Inc.