Calculation of the reaction field due to off-center point multipoles
Calculation of the reaction field due to off-center point multipoles
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DOI：
10.1063/1.474409
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发表时间：
1997-07-08
影响因子：
4.4
通讯作者：
Ponder, JW
中科院分区：
文献类型：
--
作者：
Kong, Y;Ponder, JW
提出了计算球腔中一组偏心点多极子产生的反应场的两种通用方法。这些方法是柯克伍德关于任意电荷分布的原始理论的推广。多张量公式与之前为直接多极相互作用开发的公式类似，用于组织计算并允许直接扩展到反应场能量和势梯度的更高导数。计算简化为双轴谐波的笛卡尔导数的计算。给出了计算的递归和显式公式。作为一个例子，讨论了将反应场效应纳入诱导偶极矩的计算。第二个过程是中心多极子方法，计算时间随系统规模线性扩展。还描述了基于该方法分析获得衍生物的方法。我们的开发允许使用反应场能量项和基于原子多极的经验势能函数。这两种方法都特别适合用于模拟异质系统，例如生物聚合物，其中空腔的其余部分可以明确地用溶剂填充。 (C) 1997 年美国物理研究所。
Two general methods for calculating the reaction field generated by a set of off-center point multipoles in a spherical cavity are presented. The methods are a generalization of Kirkwood's original theory for an arbitrary charge distribution. A polytensor formulation, similar to that previously developed for direct multipole interactions, serves to organize the computation and allows straightforward extension to higher derivatives of reaction field energy and gradients of the potential. The computation is reduced to calculation of the Cartesian derivatives of biaxial harmonics. Recursive and explicit formulas are given for the calculation. As an example, the incorporation of reaction field effects in computation of induced dipole moments is discussed. The second procedure, the central multipole method, scales linearly in calculation time with the size of the system. Methods to obtain derivatives analytically based on this method are also described. Our developments allow use of reaction field energy terms with atomic multipole-based empirical potential energy functions. Both methods show particular promise for use in simulation of heterogeneous systems, such as biopolymers, where the remainder of the cavity can be filled explicitly with solvent. (C) 1997 American Institute of Physics.