TREATMENT OF MULTIBODY INTERACTIONS IN MOLECULAR SIMULATIONS OF SYSTEMS WITH GENERAL BOND NETWORKS

One of the most formidable difficulties in the computer programming of molecular simulations is the sometimes complicated bookkeeping requir ed for keeping track of internal coordinates and their derivatives. A completely general method for keeping track of stretch (two-body), ben d (three-body), and torsion, wag, and other four-body interactions for ANY bond network is presented. Computer code using this method for ca lculating internal coordinates and their derivatives can be used for c ompletely different types of bond networks, no matter how complex, wit h little or no modification. The method is designed to incorporate rec ent improved formulas for calculating internal coordinates and their d erivatives to ensure the most optimal calculation sequence. (C) 1997 J ohn Wiley & Sons, Inc.