Approximate molecular electrostatic potentials from semiempirical wavefunctions

Approximate molecular electrostatic potentials (MESPs) are calculated with the asymptotic density model (ADM) on the basis of semiempirical wavefunctions generated by the SINDO1 method. The approximate MESP is adjusted to obtain good agreement with the exact MESP from 6-31G* ab initio calculations for small molecules. This form of the MESP is used for the study of the reactivity of small and medium size silicon clusters with 5 to 45 atoms. Special attention is given to the reactivity of various Si-45 structures proposed in the literature. (C) 1997 by John Wiley & Sons, Inc.