Energy and lifetime of surface plasmon from first-principles calculations

The dependence of energy and line width of Al(1 1 1) and Mg(0 0 0 1) surface plasmons on two-dimensional momenta is evaluated within an ab initio pseudopotential approach. Quantitative agreement with experimental dispersion and damping of the surface plasmon on a metal surface is obtained without any adjustable parameters taking explicitly into account both the bulk and surface electronic structures on the same basis. The study of the impact of the band structure and dynamical exchange-correlations on the surface plasmon energy and line width dispersion shows that the main effect comes from the three dimensional band structure, although to achieve quantitative agreement with experiment the inclusion of exchange-correlation effects is needed.