Stabilization of Ab Initio Molecular Dynamics Simulations at Large Time Steps

TL;DR

This paper proposes a modification to the Verlet method in ab initio molecular dynamics that enhances stability at larger time steps by limiting atomic kinetic energy, demonstrated on molten lithium fluoride.

Contribution

Introducing a kinetic energy cap in the Verlet method to improve stability of ab initio molecular dynamics at larger time steps.

Findings

Increased stability limit of Verlet method with kinetic energy cap.

Small accuracy loss with larger time steps.

Effective for molten lithium fluoride simulations.

Abstract

The Verlet method is still widely used to integrate the equations of motion in ab initio molecular dynamics simulations. We show that the stability limit of the Verlet method may be significantly increased by setting an upper limit on the kinetic energy of each atom with only a small loss in accuracy. The validity of this approach is demonstrated for molten lithium fluoride.