Electrostatic component of solvation: Comparison of SCRF continuum models

Abstract

We report a systematic comparison of the electrostatic contributions to the free energy of solvation from three different kinds of quantum mechanical self-consistent reaction field (SCRF) methods. We also compare the liquid-phase dipole moments as a measure of the solute's response to the reaction field of the solvent. In particular, we compare these quantities for the generalized Born model as implemented in the SM5.42R method, the multipolar expansion model developed at Nancy, and the MST version of the polarizable continuum model. All calculations are carried out at the HF/6-31G(d) level. The effects of various choices of solute cavities and representations of the charge density are examined. The test set consists of 18 molecules containing prototypical polar groups, and three different values of the dielectric permittivity are considered.