Microcanonical Monte Carlo approach for computing melting curves by atomistic simulations

TL;DR

This paper demonstrates that microcanonical Monte Carlo simulations can accurately determine melting points of a Lennard-Jones system, offering a simpler alternative to traditional molecular dynamics methods and expanding the applicability of the Z method.

Contribution

It introduces and validates the use of microcanonical Monte Carlo for computing melting curves, showing it matches standard methods and does not require Hamiltonian dynamics.

Findings

Microcanonical Monte Carlo accurately predicts melting temperatures.

Results align with molecular dynamics methods within temperature fluctuations.

The approach broadens the applicability of the Z method for melting point determination.

Abstract

We report microcanonical Monte Carlo simulations of melting and superheating of a generic, Lennard-Jones system starting from the crystalline phase. The isochoric curve, the melting temperature $T_m$ and the critical superheating temperature $T_{LS}$ obtained are in close agreement (well within the microcanonical temperature fluctuations) with standard molecular dynamics one-phase and two-phase methods. These results validate the use of microcanonical Monte Carlo to compute melting points, a method which has the advantage of only requiring the configurational degrees of freedom. Our findings show that the strict preservation of the Hamiltonian dynamics does not constitute a necessary condition to produce a realistic estimate of $T_{LS}$ and the melting point, which brings new insight on the nature of the melting transition. These results widen the use and applicability of the recently developed Z method for the determination of the melting points of materials.