Fitting Molecular Electrostatic Potentials from Quantum Mechanical Calculations

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• 作者：Hao Hu ; Zhenyu Lu ; Weitao Yang
• 刊名：Journal of Chemical Theory and Computation
• 出版年：2007
• 出版时间：May 2007
• 年：2007
• 卷：3
• 期：3
• 页码：1004 - 1013
• 全文大小：176K
• 年卷期：v.3,no.3(May 2007)
• ISSN：1549-9626

文摘

We develop here a new method to fit the molecular electrostatic potentials obtainedin quantum mechanical calculations to a set of classical electrostatic multipoles, usually pointcharges located at atomic positions. We define an object function of fitting as an integration ofthe difference of electrostatic potentials in the entire 3-dimensional physical space. The objectfunction is thus rotationally invariant with respect to the molecular orientation and varies smoothlywith respect to molecular geometric fluctuations. Compared with commonly employed methodssuch as the Merz-Singh-Kollman and CHELPG schemes, this new method, while possessingcomparable accuracy, shows greatly improved numerical stability with respect to the molecularpositions and geometries. The method can be used in the fitting of electrostatic potentials forthe molecular mechanics force fields and also can be applied to the calculation of electrostaticpolarizabilites of molecular or atomic systems.