Rational determination of charge distributions for free energy calculations
Rational determination of charge distributions for free energy calculations
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DOI：
10.1002/jcc.10207
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发表时间：
2003-03-01
影响因子：
3
通讯作者：
Chipot, C
中科院分区：
文献类型：
--
作者：
Chipot, C
来自 RHF/6-31G* 静电势的点电荷很有吸引力，因为它们往往会夸大溶剂化分子的极性，从而以平均方式补偿缺失的感应效应。在自由能计算的背景下，其中分子从极性环境转移到非极性环境，我们提出了一种基于更高理论水平的自洽反应场计算的更合理的方法，并辅以相应的畸变能量的估计来解释周围环境极性的变化。将该方法应用于乙酰胺、乙酸、乙酸甲酯和苯酚的测试案例，使用多纳秒分子动力学/“伞采样”模拟，产生一致的水合自由能，与实验相当吻合。 (C) 2003 年 Wiley 期刊公司。
Point charges derived from RHF/6-31G* electrostatic potentials are attractive because they tend to exaggerate the polarity of solvated molecules, thereby compensating in an average fashion missing induction effects. In the context of free energy calculations, wherein the molecule is transferred from a polar environment to a nonpolar one, we propose a more rational approach based on a self-consistent reaction field computation at a higher level of theory, supplemented by an estimation of the corresponding distortion energy to account for the change of polarity of the surroundings. Application of this method to the test cases acetamide, acetic acid, methyl acetate and phenol, using multinanosecond molecular dynamics/"umbrella sampling" simulations, yields consistent hydration free energies in reasonably good agreement with experiment. (C) 2003 Wiley Periodicals, Inc.