Solid-liquid interface free energy through metadynamics simulations

TL;DR

This paper introduces a new, efficient metadynamics-based method to accurately compute solid-liquid interface free energy, overcoming previous computational challenges and validated on Lennard-Jones systems.

Contribution

A novel approach using free energy maps from metadynamics to determine b3_{sl}, offering simplicity, robustness, and unbiased uncertainty estimation.

Findings

Confirmed previous reliable data for Lennard-Jones systems

Method is simple, robust, and free of hysteresis issues

Effective with small system sizes of a few hundred atoms

Abstract

The solid-liquid interface free energy \gamma sl is a key parameter controlling nucleation and growth during solidification and other phenomena. There are intrinsic difficulties in obtaining accurate experimental values, and the previous approaches to compute \gamma sl with atomistic simulations are computationally demanding. We propose a new approach, which is to obtain \gamma sl from a free energy map of the phase transition reconstructed by metadynamics. We apply this to the benchmark case of a Lennard-Jones potential and the results confirm the most reliable data obtained previously. We demonstrate several advantages of our new approach: it is simple to implement, robust and free of hysteresis problems, it allows a rigorous and unbiased estimate of the statistical uncertainty and it returns a good estimate of of the thermodynamic limit with system sizes of a just a few hundred atoms. It is therefore attractive for using with more realistic and specific models of interatomic forces.