AN IMPROVED DESCRIPTION OF THE MOLECULAR CHARGE-DENSITY IN FORCE-FIELDS WITH ATOMIC MULTIPOLE MOMENTS

Atomic multipole moments, calculated from ab initio wave functions, offer an attractive way toward an improvement of the description of electrostatic interactions in force-field programs. Accordingly, we have implemented the formulas for calculation of energies, forces, and torques resulting from the interactions of multipoles up to quadrupole-quadrupole interactions in our force-field program MOMO. The method was successfully applied to various problems, including conformational analysis, hydrogen bonding, and pi(-)pi interactions. (C) 1995 by John Wiley & Sons, Inc.