AB-INITIO CALCULATION OF THE PHONON-DISPERSION IN BULK INP AND IN THE INP(110) SURFACE

An ab initio linear-response approach based on the density-functional theory has been used to investigate the dynamics of bulk InP and of the InP(110) surface. The plane-wave pseudopotential method together with the slab supercell description for the surface have been employed in order to determine the complete bulk phonon spectrum, the atomic geometry of the InP(110) surface, and the surface phonon dispersion in a consistent formalism. The calculated structural and dynamical properties of both the bulk and the surface compare very well with all available experimental data. Furthermore, we examine the influence of the structural details of InP(110) on the surface vibrational features. Our ab initio results indicate the fingerprints of the relaxation geometry in the surface phonon dispersion.