| Abstract
| - Electrostatic solvation free energies are calculatedusing a self consistent reaction field (SCRF) procedurethat combines a continuum dielectric model of the solvent with bothHartree−Fock (HF) and density functionaltheory (DFT) for the solute. Several molecules are studied inaqueous solution. They comprise threegroups: nonpolar neutral, polar neutral, and ionic. Thecalculated values of ΔGel are sensitive to theatomicradii used to define the solute molecular surface, particularly to thevalue of the hydrogen radius. However,the values of ΔGel exhibit reasonable correlation withexperiment when a previously determined, physicallymotivated set of atomic radii were used to define the van der Waalssurface of the solute. The standarddeviation between theory and experiment is 2.51 kcal/mol for HF and2.21 kcal/mol for DFT for the 14molecules examined. The errors with HF or DFT are similar.The relative difference between the calculatedvalues of ΔGel and experiment is largest for nonpolarneutral molecules, intermediate for polar neutralmolecules,and smallest for ions. This is consistent with the expectedrelative importance of nonelectrostatic contributionsto the free energy that are omitted in the model.
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