High-pressure Debye-Waller and Grueneisen parameters of Au and Cu

TL;DR

This study uses first-principles calculations to analyze lattice vibrations and phonon properties of Au and Cu at high pressure, providing insights into their Debye-Waller and Grueneisen parameters.

Contribution

It introduces a method to accurately determine phonon moments and Grueneisen parameters at high pressure using short-ranged force constant models.

Findings

Phonon moments can be accurately obtained from short-range force constants.

Calculated Grueneisen parameters are consistent with experimental data.

Implications for high-pressure lattice dynamics are discussed.

Abstract

The lattice vibrations are determined in the quasi-harmonic approximation for elemental Au and Cu to twice their normal density by first-principles electronic band-structure calculations. It is found for these materials that the important moments of the phonon density of states can be obtained to high accuracy from short-ranged force constant models. We discuss the implications for the Grueneisen parameters on the basis of calculated phonon moments and their approximations by using bulk moduli and Debye-Waller factors.