Evaluating the properties of nucleating liquid drops by Monte Carlo simulation

Abstract

Nucleation is the mechanism controlling first order phase transitions and involves the formation of a small critical cluster. Its energy of formation dictates the nucleation rate, but it is difficult to evaluate since the critical cluster is unstable. Here, we develop a new Monte Carlo simulation technique to study the properties of critical droplets and compute their free energy of formation. In particular, we studied a Lennard-Jones fluid with truncated and shifted potential at 2.5 σ (LJTS(2.5 σ)), confined in a small volume at reduced temperature T = 0.625. We compare our results for the work of formation to previous data for this system obtained with Umbrella Sampling (US), obtaining good agreement. Our findings suggest that this new technique is particularly promising for investigating small critical clusters relevant to experimental conditions and complex atmospheric fluids, where traditional methods are computationally demanding