Ab initio study of Be (1010) surface dynamical properties

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