An accurate and efficient procedure of fitting electric field potential by point charges for QM/MM calculations

摘要

An accurate and efficient computational procedure of fitting an electric field potential given on the grid in a finite QM cavity of arbitrary shape by point charges is described. The charges are located on the surface of the sphere that encloses the QM cavity, and also inside the sphere, but outside the QM cavity. The procedure is based on the use of spherical harmonics and singular value decomposition. An example of application of the procedure in QM/MM calculations of pKa values in proteins is discussed. (c) 2006 WILEY-VCH Vertag GmbH & Co. KGaA, Weinheim.