ON THE EVALUATION OF THE SOLVENT POLARIZATION APPARENT CHARGES IN THEPOLARIZABLE CONTINUUM MODEL - A NEW FORMULATION

A new formulation (CLS-PCM) for the calculation of the apparent surfac e charges in the framework of the ab initio polarizable continuum mode l of the solvent (PCM) is introduced. Its performance is compared with that of the original iterative version (ITER-PCM) of the method as we ll as with a matricial alternative formulation (matrix-BEM-PCM) of the same problem. Both CLS-PCM and matrix-BEM-PCM have shown to be comput ationally more efficient than ITER-PCM without presenting any problems associated with the convergence of the process. Although for small an d medium-size solutes the use of matrix-BEM-PCM is recommended, for ne utral solutes of larger size the use of CLS2 becomes computationally m ore convenient. Finally, for very large-size systems, compromise betwe en matrix storage requirements, time of calculation, and exactness of the results may make preferable the use of the more approximate CLS1 f ormalism, possibly in conjunction with semiempirical or semiclassical descriptions of the solute. (C) 1995 by John Wiley and Sons, Inc.