VOLUME POLARIZATION IN REACTION FIELD-THEORY

Citation
Cg. Zhan et al., VOLUME POLARIZATION IN REACTION FIELD-THEORY, The Journal of chemical physics, 108(1), 1998, pp. 177-192
Citations number
37
Categorie Soggetti
Physics, Atomic, Molecular & Chemical
ISSN journal
00219606
Volume
108
Issue
1
Year of publication
1998
Pages
177 - 192
Database
ISI
SICI code
0021-9606(1998)108:1<177:VPIRF>2.0.ZU;2-J
Abstract
In continuum reaction field models of solvation, unconstrained quantum mechanical calculation of the solute electronic structure inevitably leads to penetration of some solute charge density outside the cavity and into the solvent dielectric region. This produces a rarely recogni zed or treated volume polarization that contributes in addition to the commonly considered surface polarization. In this work a new practica l implementation is described for quantitatively evaluating both volum e and surface polarization contributions to the solute-solvent interac tion with an irregularly shaped cavity surface. For illustration, nume rical results are presented on several representative small neutral, c ation, and anion solutes. The volume polarization contributions to ene rgies and dipole moments are found to be somewhat smaller than those f rom surface polarization, but not negligible. The results are also use d to test several charge renormalization approaches that have been pre viously proposed in the literature. Compared to the exact volume polar ization correction, these can sometimes lead to energy corrections of the wrong sign. A previously proposed method of simulating volume pola rization through an additional surface polarization generally produces corrections of the right sign and of about the right magnitude. (C) 1 998 American Institute of Physics.