Phase diagram and universality of the Lennard-Jones gas-liquid system

TL;DR

This study uses molecular dynamics simulations to analyze the phase diagram and critical behavior of the Lennard-Jones gas-liquid system, confirming its universality class and accurately determining critical parameters.

Contribution

It provides high-precision measurements of coexisting densities, critical exponents, and confirms the universality class of the Lennard-Jones gas-liquid transition.

Findings

Critical exponents match Ising universality class

Accurate determination of coexistence densities

Critical point identified via Binder parameter analysis

Abstract

The gas-liquid phase transition of the three-dimensional Lennard-Jones particles system is studied by molecular dynamics simulations. The gas and liquid densities in the coexisting state are determined with high accuracy. The critical point is determined by the block density analysis of the Binder parameter with the aid of the law of rectilinear diameter. From the critical behavior of the gas-liquid coexsisting density, the critical exponent of the order parameter is estimated to be $\beta = 0.3285(7)$. Surface tension is estimated from interface broadening behavior due to capillary waves. From the critical behavior of the surface tension, the critical exponent of the correlation length is estimated to be $\nu = 0.63 (4)$. The obtained values of $\beta$ and $\nu$ are consistent with those of the Ising universality class.