Ab-initio dynamical properties of the Be(0001) surface

We present a first-principles calculation of the dynamical properties of the Be(0001) surface, as obtained by state of the art density-functional perturbation theory. We calculate the dynamical properties of fully relaxed 12-layer Be slabs, and find significantly different results from those obtained using a bulk-truncated geometry. Our results are in excellent agreement with recent EELS experiments, and show that three layers are involved in the surface dynamics, (C) 1998 Elsevier Science B.V. All rights reserved.