Ab initio study of Be (1010) surface dynamical properties

We present a first-principles calculation of the dynamical properties of the Be (10 (1) over bar 0) surface, as obtained by state-of-the-art density functional perturbation theory. While calculations based on truncated bulk models do not agree with recent electron energy loss spectroscopy experimental measurements, failing to predict even the Rayleigh wave dispersion at zone boundaries, our fully ab initio calculation predicts the correct energies for these and other surface modes. Some of the measured resonances around the Brillouin zone center do not correspond to single localized surface modes but can be identified as due to a high surface density of vibrational states. (C) 2000 Elsevier Science B.V. All rights reserved