Solvent effects on molecular electric properties

Abstract

Theoretical background and applications of methods for the calculation of solvent effects on molecular electric properties are reviewed. Macroscopic linear and nonlinear susceptibilities are defined, and their relationship to microscopic properties, i.e., (hyper)polarizabilities, is described. The role of specific intermolecular interactions in property calculations is demonstrated in terms of interaction-induced properties. Two categories of models for the description of solvent effects are presented. The first category comprises continuum models, in which the solvent is described as a homogeneous medium with the solute molecule located inside a cavity. Within this category, the polarizable continuum model and the multipole expansion method are described in more detail. The second group of approaches is based on discrete solvent models in which the solvent molecules are explicitly considered. Selected representative methods such as the supermolecular approach, polarizable embedding, and frozen-density embedding are presented. The possibility to combine explicit and implicit methods is demonstrated on the discrete reaction field and the Langevin dipole approaches. Finally, two illustrative examples (liquid water and p-nitroaniline in 1, 4-dioxane) of the application of the presented methods for (non)linear property calculations are given.