Glass and Time, IMFUFA, Department of Science and Environment, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark.
J Chem Phys. 2018 Sep 21;149(11):114501. doi: 10.1063/1.5043546.
It was recently shown that the exponentially repulsive EXP pair potential defines a system of particles in terms of which simple liquids' quasiuniversality may be explained [A. K. Bacher , Nat. Commun. , 5424 (2014); J. C. Dyre, J. Phys.: Condens. Matter , 323001 (2016)]. This paper and its companion [A. K. Bacher , J. Chem. Phys. , 114502 (2018)] present a detailed simulation study of the EXP system. Here we study how structure monitored by the radial distribution function and dynamics monitored by the mean-square displacement as a function of time evolve along the system's isotherms and isochores. The focus is on the gas and liquid phases, which are distinguished pragmatically by the absence or presence of a minimum in the radial distribution function above its first maximum. A constant-potential-energy ()-based proof of quasiuniversality is presented, and quasiuniversality is illustrated by showing that the structure of the Lennard-Jones system at four state points is well approximated by those of EXP pair-potential systems with the same reduced diffusion constant. Paper II studies the EXP system's isomorphs, focusing also on the gas and liquid phases.
最近有人指出，指数排斥 EXP 对势定义了一个粒子系统，据此可以解释简单液体的准普遍性[A. K. Bacher，Nat. Commun.，5424 (2014)；J. C. Dyre，J. Phys.: Condens. Matter，323001 (2016)]。本文及其伴随论文[A. K. Bacher，J. Chem. Phys.，114502 (2018)]对 EXP 系统进行了详细的模拟研究。在这里，我们研究了径向分布函数监测的结构和随时间演化的均方位移作为系统等温线和等容线的函数。重点是气体和液体相，这是通过在径向分布函数的第一个最大值之上是否存在最小值来实用地区分的。提出了一种基于恒势能量()的准普遍性证明，并通过展示在四个状态点处 Lennard-Jones 系统的结构可以很好地被具有相同的约化扩散常数的 EXP 对势系统的结构来近似，说明了准普遍性。论文 II 研究了 EXP 系统的同素物，也关注气体和液体相。
