The EXP pair-potential system. I. Fluid phase isotherms, isochores, and quasiuniversality

The exponentially repulsive EXP pair potential defines a system of particles in terms of which simple liquids' quasiuniversality may be explained [A. K. Bacher et al., Nat. Commun. 5, 5424 (2014); J. C. Dyre, J. Phys. Condens. Matter 28, 323001 (2016)]. This paper and its companion present a de...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2018-07
Main Authors: Andreas Kvist Bacher, Schrøder, Thomas B, Dyre, Jeppe C
Format: Article
Language:English
Subjects:
Distribution functions
Dynamic structural analysis
Isotherms
Liquid phases
Radial distribution
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The exponentially repulsive EXP pair potential defines a system of particles in terms of which simple liquids' quasiuniversality may be explained [A. K. Bacher et al., Nat. Commun. 5, 5424 (2014); J. C. Dyre, J. Phys. Condens. Matter 28, 323001 (2016)]. This paper and its companion present a detailed simulation study of the EXP system. Here we study how structure monitored via the radial distribution function and dynamics monitored via 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. An NVU-based proof of quasiuniversality is presented, and quasiuniversality is illustrated by showing that the structure of the Lennard-Jones system at four selected state points is well approximated by those of EXP pair-potential systems with the same reduced diffusion constant. The companion paper studies the EXP system's isomorphs, focusing also on the gas and liquid phases.
ISSN:2331-8422
DOI:10.48550/arxiv.1807.10959