REGISTRATION, ORIENTATION, AND SIMILARITY OF MOLECULAR ELECTROSTATIC POTENTIALS THROUGH MULTIPOLE MATCHING

The use of a multipolar decomposition of the far electrostatic potenti al for the purposes of molecular field similarity comparison between s tructurally different molecules has been impractical because the multi polar decomposition depends on the center of expansion. That center of expansion is essentially arbitrary, which renders the multipolar coef ficients to be a nonunique characterization of the field. This article provides the definition of a center of expansion at which the multipo lar decomposition is unique. For the first time, it is possible to use multipolar decomposition to characterize molecular fields beyond the first term, which is invariant under translation of the center of expa nsion. Calculations are performed for two structurally distinct types of HIV-1 inhibitors, three nonnucleoside reverse transcriptase inhibit ors, and three phospholipids using these unique multipolar descriptors . Differences and similarities in the calculated values of these descr iptors will be shown to parallel the differences and similarities of m olecular charge distributions. (C) 1996 by John Wiley & Sons, Inc.