The pressure dependence of the phonon spectra and elastic modulus of orthorhombic : the method of local density functional

TL;DR

This study uses density functional theory to analyze how hydrostatic pressure affects phonon spectra and elastic properties of orthorhombic GeSe, revealing a structural phase transition at around 29 GPa.

Contribution

It applies the local density functional method to predict pressure-induced changes in phonon spectra and elastic constants of GeSe, including a phase transition.

Findings

Phonon frequencies and elastic constants vary with pressure.

A continuous structural transition occurs at approximately 29 GPa.

The study compares theoretical results with experimental data.

Abstract

The IR- and Raman-active phonon frequencies, as well as the elastic constants of orthorhombic GeSe, were calculatedas a function of hydrostatic pressure using the method of density functional in the ABINIT software package. Comparison with the published results of theoretical calculations and experimental data of the pressure dependence of Raman-active phonons has been carried out. Our calculations show that at a pressure of about 29 GPa the crystal structure of GeSe undergoes a continuous transition from simple orthorhombic to base-centered orthorhombic lattice.