THE IMPLEMENTATION OF DENSITY-FUNCTIONAL THEORY WITHIN THE POLARIZABLE CONTINUUM MODEL FOR SOLVATION

The implementation of density functional theory within the polarizable continuum model for solvation reported. Test calculations are performed on a set of representative compounds and the resulting free energies of hydration, DELTAG(hydr), are compared with experimental data and Hartree-Fock calculations. Two gradient-corrected functionals are considered and are found to assure an improved description of the solute-solvent electrostatic interactions with respect to the Hartree-Fock results. The mean square root deviation of the DELTAG(hydr) values with respect to experimental values is found to be only 0.78 kcal/mol (respectively 0.77 kcal/mol) utilizing the Becke functional for exchange and the Perdew functional (respectively the Lee-Yang-Parr functional) for correlation, whereas it is 1.97 kcal/mol at the Hartree-Fock level.