| Abstract |
A parametrization of the polarizable continuum model (PCM) is presented having the experimental hydration free energies of 215 neutral molecules as target. The cavitation and dispersion contributions were based on the Tunon-Silla-Pascual-Ahuir (Tunon; et al. Chem. Phys. Lett. 1993, 203, 289) and Floris-Tomasi (Floris, F.; Tomasi, J. J. Comput. Chem. 1989, 10, 616) expressions, respectively. Both the polar and nonpolar contributions were evaluated on the same solvent-excluding molecular surface that used unsealed Bondi atomic radii. The parametrization was provided for the HF, X alpha, LSDA, B3LYP, and mPW1PW91 methods at the 6-31G(d) basis set, and the results are in fair agreement with the experimental data. For the sake of comparison, the PCM(UAHF) and our parametrization (PCM2), both at HF level, have produced Delta G(PCM(UAHF)) = a Delta G(exp) (a = 1.02 +/- 0.02, r = 0.945, sd = 0.987, F-test = 1778) and Delta G(PCM2) = a Delta G(exp) (a = 0.95 +/- 0.02, r = 0.952, sd = 0.843, F-test = 2070), respectively. The mean absolute deviations from experimental data were 0.67 and 0.68 kcal/mol for PCM(UAHF) and PCM2, respectively. |
