Dispersion and repulsion contributions to the solvation free energy: comparison of quantum mechanical and classical approaches in the polarizable continuum model.

TitleDispersion and repulsion contributions to the solvation free energy: comparison of quantum mechanical and classical approaches in the polarizable continuum model.
Publication TypeJournal Article
Year of Publication2006
AuthorsCurutchet, Carles, Orozco Modesto, F Luque Javier, Mennucci Benedetta, and Tomasi Jacopo
JournalJ Comput Chem
Volume27
Pagination1769-80
Date Published2006 Nov 30
ISSN0192-8651
KeywordsAcetaldehyde, Chemical, Ethane, Fluorobenzenes, Models, Quantum Theory, Solutions, Thermodynamics
Abstract

We report a systematic comparison of the dispersion and repulsion contributions to the free energy of solvation determined using quantum mechanical self-consistent reaction field (QM-SCRF) and classical methods. In particular, QM-SCRF computations have been performed using the dispersion and repulsion expressions developed in the framework of the integral equation formalism of the polarizable continuum model, whereas classical methods involve both empirical pairwise potential and surface-dependent approaches. Calculations have been performed for a series of aliphatic and aromatic compounds containing prototypical functional groups in four solvents: water, octanol, chloroform, and carbon tetrachloride. The analysis is focused on the dependence of the dispersion and repulsion components on the level of theory used in QM-SCRF computations, the contribution of those terms in different solvents, and the magnitude of the coupling between electrostatic and dispersion-repulsion components. Finally, comparison is made between the dispersion-repulsion contributions obtained from QM-SCRF calculations and the results determined from classical approaches.

DOI10.1002/jcc.20480