Correction of Density-Functional-Theory based polynomial interatomic potentials to reproduce experimental melting properties

TL;DR

This paper introduces a method to modify polynomial interatomic potentials derived from ab-initio calculations to accurately reproduce experimental melting temperatures while maintaining laser excitation modeling accuracy.

Contribution

It presents a correction approach for polynomial potentials to match experimental melting properties without losing ab-initio accuracy in laser excited scenarios.

Findings

Corrected silicon potential reproduces experimental melting temperature.

Method maintains accuracy for laser-induced nonthermal effects.

Potential accurately models temperature and pressure dependence.

Abstract

Recently, we developed a method to construct polynomial interatomic potentials from ab-initio calculations in order to accurately describe laser excited solids [PRL 124, 085501 (2020)]. However, ab-initio methods, and therefore analytical potentials derived from them, commonly do not provide an accurate prediction of the melting temperature. In order to reproduce the experimental melting properties, but keeping the accuracy in the laser excited case, we present here an approach to modify few key coefficients of polynomial interatomic potentials constructed from ab-initio data. We show that, with the help of such corrections, the electronic-temperature dependent interatomic potential for silicon can, at the same time, describe nonthermal laser induced effects with ab-initio accuracy and also provide the correct experimental melting temperature and slope $dT/dp$.