Energy loss of charged particles moving parallel to a magnesium surface: Ab initio calculations

We present ab initio calculations of the electronic energy loss of charged particles moving outside a magnesium surface from a realistic description of the one-electron band structure and a full treatment of the dynamical electronic response of valence electrons. Our results indicate that the finite width of the plasmon resonance, which is mainly due to the presence of band-structure effects, strongly modifies the asymptotic behavior of the energy loss at large distances from the surface. This effect is relevant for the understanding of the interaction between charged particles and the internal surface of microcapillaries.