First principles implementation of solvent effects without outlying charge error

In this work, we present a sound modified implementation of the noniterative approach for the inclusion of solvent effects for molecular-shaped cavities in conventional ab initio gas phase computations. This model will serve as the starting point from which to add additional influences such as nonelectrostatic and correlation effects, as well as optimization of cavity radii. The improvement over recent dielectric continuum models is (a) the utilization of distributed multipoles up to hexadecapoles for the generation of the potential on the cavity boundary to the dielectric and the calculation of surface charges, and (b) an accurate assessment of outlying charge effects. The new method is tested in calculations of salvation energies and geometries for a number of neutral and charged molecules. (C) 1997 American Institute of Physics.