New fitting scheme to obtain effective potential from Car-Parrinello molecular dynamics simulations: Application to silica

TL;DR

This paper introduces a novel fitting scheme to derive effective potentials from Car-Parrinello molecular dynamics, successfully applied to silica, resulting in a potential that accurately reproduces structural, dynamic, and elastic properties.

Contribution

A new fitting method for extracting effective potentials from CPMD simulations, demonstrated by developing a transferable silica potential that matches experimental and high-level simulation data.

Findings

Accurately reproduces liquid structure from CPMD trajectories

Matches experimental activation energies and density of silica

Replicates lattice parameters and elastic constants of alpha-quartz

Abstract

A fitting scheme is proposed to obtain effective potentials from Car-Parrinello molecular dynamics (CPMD) simulations. It is used to parameterize a new pair potential for silica. MD simulations with this new potential are done to determine structural and dynamic properties and to compare these properties to those obtained from CPMD and a MD simulation using the so-called BKS potential. The new potential reproduces accurately the liquid structure generated by the CPMD trajectories, the experimental activation energies for the self-diffusion constants and the experimental density of amorphous silica. Also lattice parameters and elastic constants of alpha-quartz are well-reproduced, showing the transferability of the new potential.