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Advancing beyond the atom‐centered model in additive and nonadditive molecular mechanics
Author(s) -
Dixon Richard W.,
Kollman Peter A.
Publication year - 1997
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/(sici)1096-987x(199710)18:13<1632::aid-jcc5>3.0.co;2-s
Subject(s) - lone pair , solvation , chemistry , computational chemistry , statistical mechanics , hydrogen bond , statistical physics , atomic physics , physics , molecule , quantum mechanics
A computational approach to the inclusion of off‐center charges in both additive and nonadditive molecular mechanics calculations is presented. The additional sites in the molecular skeleton are placed in the approximate locations of the chemically intuitive electron lone pair, and are treated as formal particles throughout the calculation. The increase in the number of charge sites results in overall improvement in the energy associated with the angular dependence of hydrogen bonds and improved statistical accuracy of the electrostatic potential derived charges. The addition of lone pairs also results in improved accuracy in relative solvation free energy calculation for the pyridine to benzene and methanol to methane mutations. Because the number of atoms that require lone pairs is small, the extra accuracy can be achieved with little computational overhead. © 1997 John Wiley & Sons, Inc. J Comput Chem 18 : 1632–1646, 1997