Chemical Potential Calculations In Dense Liquids Using Metadynamics

TL;DR

This paper introduces a metadynamics-based approach to efficiently calculate chemical potentials in dense liquids, overcoming limitations of traditional insertion methods like Widom's in high-density systems.

Contribution

The paper presents a novel application of metadynamics to improve chemical potential calculations in dense fluids, enabling convergence where Widom's method fails.

Findings

Metadynamics increases insertion probability in dense fluids.

Efficient convergence of chemical potential calculations achieved.

Method successfully applied to a supercooled high-density Lennard-Jones fluid.

Abstract

The calculation of chemical potential has traditionally been a challenge in atomistic simulations. One of the most used approaches is Widom's insertion method in which the chemical potential is calculated by periodically attempting to insert an extra particle in the system. In dense systems this method fails since the insertion probability is very low. In this paper we show that in a homogeneous fluid the insertion probability can be increased using metadynamics. We test our method on a supercooled high density binary Lennard-Jones fluid. We find that we can obtain efficiently converged results even when Widom's method fails.