A quantitative theory and atomistic simulation study on the soft-sphere crystal-melt interfacial properties. II. Interfacial free energies

Abstract

This study proposes a new method for predicting the crystal-melt interfacial free energy (γ) using the Ginzburg–Landau (GL) model, enhanced by atomistic simulation data for more accurate density wave profiles. The analysis focuses on the soft-sphere system governed by an inverse power potential that stabilizes both BCC and FCC phases. Equilibrium molecular-dynamics simulations are used to obtain density-wave amplitude distributions, which serve as inputs for the GL model to predict γ and its anisotropy. The predicted γ values exhibit strong agreement with prior benchmark simulation experimental studies, particularly for FCC crystal–melt interfaces (CMIs). The GL models for the CMI γ are proved to be both computationally efficient and reasonable, offering quantitative predictions of γ while providing insights into the factors controlling its magnitude and anisotropy. Key improvement is suggested for the variational procedure used in the two-mode CMI free energy functionals, and potential upgrades to the GL model are also proposed to further enhance predictive accuracy.