  Solvation free energy is an important quantity in Computational Chemistry
with a variety of applications, especially in drug discovery and design. The
accurate prediction of solvation free energies of small molecules in water is
still a largely unsolved problem, which is mainly due to the complex nature of
the water-solute interactions. In this letter we develop a scheme for the
determination of the electrostatic contribution to the solvation free energy of
charged molecules based on nonlocal electrostatics involving a minimal
parameter set which in particular allows to introduce atomic radii in a
consistent way. We test our approach on simple ions and small molecules for
which both experimental results and other theoretical descriptions are
available for quantitative comparison. We conclude that our approach is both
physically transparent and quantitatively reliable.
