Pseudopotential study of barium chalcogenides under hydrostatic pressure

Abstract

We present first-principles calculations within the pseudo-potential plane wave method in the local density approximation (LDA) and the generalised gradient approximation so as to study the structural properties of BaX (X=S, Se and Te) in both NaCl and CsCl structures. The elastic, vibrational properties and lattice dynamics are calculated with the LDA and the density functional perturbation theory. The pressure dependence of the structural, vibrational and lattice dynamics has been investigated by varying the volume. A good agreement is obtained between our calculation and the available experimental and theoretical data.

Keywords:

• ab initio calculation
• lattice dynamics
• phonons
• high pressure
• BaSe
• BaS
• BaTe

Acknowledgements

The authors wish to express their sincere thanks to Professor A. Muñoz and his team for their computer facilities.

Notes

The ABINIT computer code is a common project of the Universite Catholique de Louvain, Corning Incorporated and other contributors. Available at http://www.abinit.org.