Molecular Dynamics on Diffusive Time Scales from the Phase Field Crystal Equation

TL;DR

This paper extends the phase field crystal model to simulate atomic configurations and vacancies, enabling molecular dynamics on diffusive time scales through solving a PDE, demonstrated by calculating a liquid's two-point correlation function.

Contribution

It introduces a non-negative order parameter in the phase field crystal model to accurately represent atomic configurations and vacancies, bridging phase field methods with molecular dynamics.

Findings

Successfully modeled atomic configurations and vacancies.

Performed molecular dynamics simulations on diffusive time scales.

Calculated the two-point correlation function of a liquid.

Abstract

We extend the phase field crystal model to accommodate exact atomic configurations and vacancies by requiring the order parameter to be non-negative. The resulting theory dictates the number of atoms and describes the motion of each of them. By solving the dynamical equation of the model, which is a partial differential equation, we are essentially performing molecular dynamics simulations on diffusive time-scales. To illustrate this approach, we calculate the two-point correlation function of a liquid.