Nonempirical calculations of nonlinear optical properties of p-nitroaniline in acetone:: Comparison of supermolecule and semicontinuum approaches

The comparison of the conventional continuum, supermolecule, and semicontinium models for the description of solvent effect on the (hyper)polarizabitity of p-nitroaniline (PNA) in acetone is performed. The supermolecule approach is used for the clusters containing PNA and one or two acetone molecules. The account of the specific solute-solvent interactions via the hydrogen bonds formation is shown to result in the enhancement of (hyper)polarizability values. The continuum approach exploited in the framework of polarizable continuum model (PCM) was shown to describe mainly the solvent effect on (hyper)polarizabihty. The sernicontinium approach, accounting explicitly the interaction between PNA and solvent molecules and treating the rest of the solvent as a continuum, results in a moderate increase of the (hyper)polarizabihty values compared to those obtained within the conventional PCM approach. All the calculations of (hyper)polarizabihties are performed at the Hartree-Fock level in the aug-cc-pVDZ' Dunning basis set. (c) 2007 Wiley Periodicals, Inc.