New assignment of parameters for charge equilibration approach

COMP 98

Naofumi Nakayama, nakayama@cochem2.tutkie.tut.ac.jp and Hitoshi Goto, gotoh@cochem2.tutkie.tut.ac.jp. Department of Knowledge-based Information and Engineering, Toyohashi University of Technology, Toyohashi, 441-8580, Japan
The charge equilibration (QEq) approach proposed by Rappé and Goddard on 1991 is well known as the method that estimates the charge distribution according to the dynamical changes of the molecular geometry. Recently, we proposed new framework of QEq, named NQEq, that the empirical formula of Coulomb interaction is employed and that the parameter set is divided into each atom types based on Merck Molecular Force Field (MMFF). In this study, we propose new procedure of determination of parameters for NQEq based on the bond polarizabilities. 868 dipole moment components for 456 molecular conformers (404 molecules) are calculated by this method and compared with those obtained by MP2/6-31G**. Root-mean-square of difference of computational values between by MP2 and by NQEq is 0.22.