High Pressure Research Vol. 27, No. 2, June 2007, 269–277 Ab initio calculation of the lattice dynamics of the Boron group-V compounds under high pressure K. BOUAMAMA*†, P. DJEMIA‡, N. LEBGA§ and K. KASSALI† †Laboratoire d’optoélectronique et composant, Département de Physique, Université Ferhat Abbas, 19000 Sétif, Algeria ‡Laboratoire des Propriétés Mécaniques et Thermodynamiques des Matériaux, UPR CNRS 9001, Université Paris-Nord,Avenue J.-B. Clément, 93430 Villetaneuse, France §Institut de Tronc Commun de Sciences et Technologie, Centre Universitaire Bordj Bou-Arreridj, 34000 El-Annaseur, Algeria (Received 5 June 2006; revised 6 February 2007; in final form 7 February 2007) High-pressure effects on the lattice dynamics and dielectric properties of the BN, BP, BAs, BSb and BBi alloys have been carried out using the density-functional perturbation theory within the local density approximation. We study the variation of the optical phonon frequencies (ω TO and ω LO ), the high-frequency dielectric coefficient (ǫ ∞ ) and the dynamic effective charge (Z ∗ ) with pressure. The ω TO and ω LO have a quadratic form with pressure for all boron compounds. The obtained ǫ ∞ and Z ∗ for BN, BP remain constant with pressure. However, for BAs, BSb and BBi, ǫ ∞ and Z ∗ have a quadratic form with pressure. Our results are in good agreement with the available experimental data for BN and BP and they allow prediction for BAs, BSb and BBi. Keywords: Phonon; Boron compounds; Density functional theory PACS: 63.20Dj; 71.15Mb 1. Introduction The physical properties of boron compounds BN, BP, BAs, BSb and BBi are studied [1–10] to understand their efficiency on their application in wide gap optoelectronic technology (devices) and also to compare these properties with those of the other III–V type semiconductors. In this work, we do first-principle calculations on the effect of the pressure on the lattice dynamics and dielectric properties of boron compounds in zinc blende phase. We compare our results for BN and BP with the experimental ones [6] and we give prediction for BAs, BSb and BBi. The calculation of the transverse optical phonon frequencies ω TO and the longitu- dinal optical phonon frequencies ω LO at the Ŵ point are performed using density-functional perturbation theory (DFPT) in the plane–wave pseudopotential method using ABINIT code. The high-frequency dielectric coefficient ǫ ∞ and the dynamic effective charge Z ∗ are directly derived from the DFPT calculations. *Corresponding author. Email: khaled_bouamama@yahoo.fr High Pressure Research ISSN 0895-7959 print/ISSN 1477-2299 online © 2007 Taylor & Francis http://www.tandf.co.uk/journals DOI: 10.1080/08957950701265359