The nature of the calculation of the pressure in molecular simulations of continuous models from volume perturbations
The nature of the calculation of the pressure in molecular simulations of continuous models from volume perturbations
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DOI：
10.1063/1.2363381
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发表时间：
2006-10-28
影响因子：
4.4
通讯作者：
Jackson, George
中科院分区：
文献类型：
--
作者：
de Miguel, Enrique;Jackson, George
我们考虑一些基本方面的压力计算模拟体积摄动。该方法最初由Eppenga和Frenkel [Mol. Phys.52，1303（1984）]，然后由Harismiadis [J.Chem.Phys.105，8469（1996）]扩展到连续势，是基于与微扰相关的亥姆霍兹自由能变化的数值估计，而微扰又可以表示为相应玻尔兹曼因子的系综平均。这种方法可以很容易地推广到压力张量分量的计算，也可以推广到正则系综以外的系综。该方法的准确性进行评估，通过比较从体积扰动路线与通常的维里表达式几个原型流体模型获得的模拟结果。Monte Carlo模拟数据报告为散装流体和非均质系统包含一个汽液界面。
We consider some fundamental aspects of the calculation of the pressure from simulations by performing volume perturbations. The method, initially proposed for hard-core potentials by Eppenga and Frenkel [Mol. Phys.52, 1303 (1984)] and then extended to continuous potentials by Harismiadis [J. Chem. Phys. 105, 8469 (1996)], is based on the numerical estimate of the change in Helmholtz free energy associated with the perturbation which, in turn, can be expressed as an ensemble average of the corresponding Boltzmann factor. The approach can be easily generalized to the calculation of components of the pressure tensor and also to ensembles other than the canonical ensemble. The accuracy of the method is assessed by comparing simulation results obtained from the volume-perturbation route with those obtained from the usual virial expression for several prototype fluid models. Monte Carlo simulation data are reported for bulk fluids and for inhomogeneous systems containing a vapor-liquid interface.