Charges fit to electrostatic potentials. II. Can atomic charges be unambiguously fit to electrostatic potentials? Export

@article{citeulike:3866485, abstract = {The present work examines the conditioning of the least-squares matrix for obtaining potential derived charges and presents a modification of the CHELP method for fitting atomic charges to electrostatic potentials. Results from singular value decompositions (SVDs) of the least-squares matrices show that, in general, the least-squares matrix for this fitting problem will be rank deficient. Thus, statistically valid charges cannot be assigned to all the atoms in a given molecule. We find also that, contrary to popular notions, increasing the point density of the fit has little or no influence on the rank of the problem. Improvement in the rank can best be achieved by selecting points closer to the molecular surface. Basis set has, as expected, no effect on the number of charges that can be assigned. Finally, a well-defined, computationally efficient algorithm (CHELP-SVD) is presented for determining the rank of the least-squares matrix in potential-derived charge fitting schemes, selecting the appropriate subset of atoms to which charges can be assigned based on that rank estimate, and then refitting the selected set of charges. {\copyright} 1996 by John Wiley \& Sons, Inc.}, address = {Department of Chemistry, Bryn Mawr College, 101 N. Merion Avenue, Bryn Mawr, Pennsylvania 19010-2899; American Cyanamid Company, Agricultural Research Division, P.O. Box 400, Princeton, New Jersey 08543-0400}, author = {Francl, Michelle M. and Carey, Christina and Chirlian, Lisa E. and Gange, David M.}, citeulike-article-id = {3866485}, citeulike-linkout-0 = {http://dx.doi.org/10.1002/(SICI)1096-987X(199602)17:3%3C367::AID-JCC11%3E3.0.CO;2-H}, citeulike-linkout-1 = {http://www3.interscience.wiley.com/cgi-bin/abstract/66025/ABSTRACT}, doi = {10.1002/(SICI)1096-987X(199602)17:3%3C367::AID-JCC11%3E3.0.CO;2-H}, journal = {Journal of Computational Chemistry}, keywords = {atoms, charges, electrostatics, potentials}, number = {3}, pages = {367--383}, posted-at = {2009-07-02 12:10:10}, priority = {2}, title = {Charges fit to electrostatic potentials. II. Can atomic charges be unambiguously fit to electrostatic potentials?}, url = {http://dx.doi.org/10.1002/(SICI)1096-987X(199602)17:3%3C367::AID-JCC11%3E3.0.CO;2-H}, volume = {17}, year = {1996} }

TY - JOUR ID - citeulike:3866485 L3 - citeulike-article-id:3866485 N2 - The present work examines the conditioning of the least-squares matrix for obtaining potential derived charges and presents a modification of the CHELP method for fitting atomic charges to electrostatic potentials. Results from singular value decompositions (SVDs) of the least-squares matrices show that, in general, the least-squares matrix for this fitting problem will be rank deficient. Thus, statistically valid charges cannot be assigned to all the atoms in a given molecule. We find also that, contrary to popular notions, increasing the point density of the fit has little or no influence on the rank of the problem. Improvement in the rank can best be achieved by selecting points closer to the molecular surface. Basis set has, as expected, no effect on the number of charges that can be assigned. Finally, a well-defined, computationally efficient algorithm (CHELP-SVD) is presented for determining the rank of the least-squares matrix in potential-derived charge fitting schemes, selecting the appropriate subset of atoms to which charges can be assigned based on that rank estimate, and then refitting the selected set of charges. © 1996 by John Wiley & Sons, Inc. IS - 3 JF - Journal of Computational Chemistry AD - Department of Chemistry, Bryn Mawr College, 101 N. Merion Avenue, Bryn Mawr, Pennsylvania 19010-2899; American Cyanamid Company, Agricultural Research Division, P.O. Box 400, Princeton, New Jersey 08543-0400 EP - 383 TI - Charges fit to electrostatic potentials. II. Can atomic charges be unambiguously fit to electrostatic potentials? VL - 17 SP - 367 KW - atoms KW - charges KW - electrostatics KW - potentials AU - Francl, Michelle AU - Carey, Christina AU - Chirlian, Lisa AU - Gange, David PY - 1996/// UR - http://dx.doi.org/10.1002/(SICI)1096-987X(199602)17:3%3C367::AID-JCC11%3E3.0.CO;2-H ER -