Optimized atomic radii for quantum dielectric continuum solvation models

We present an optimized set of atomic radii for H, C, N, O, F, P, S and Cl, which can be used in quantum dielectric continuum calculations. These atomic radii yield differences in hydration energies with experimental data of about 1 kcal/mol for neutral molecules, 2 kcal/mol for cations and 2–5 kcal/mol for anions at the Hartree-Fock, second order Møller-Plesset perturbation, and various non-local density functional theories within the framework of the generalized conductor-like screening model. Almost the same accuracy was also found when these radii were used with the polarizable continuum model (PCM). The accuracy of the recently proposed self-consistent isodensity PCM model is also discussed.