TREATMENT OF THE OUTLYING CHARGE IN CONTINUUM SOLVATION MODELS

Continuum solvation models have proven to yield very valuable informat ion about solvation effects, if cavities close to the van der Waals su rface of the solutes are used for the calculation of the screening cha rges. Unfortunately, such cavity size implies that a small but signifi cant portion of the solute electron density reaches out of the cavity. This outlying charge causes serious problems in the context of the di electric continuum treatment of the solvent. The present paper present s a critical consideration of the origin, the magnitude, and the diffe rent strategies for treatment of this problem. Finally, a novel ansatz using an additional, outer cavity is presented which provides rather accurate correction of the corresponding error. (C) 1996 American Inst itute of Physics.