Energy loss of charged particles interacting with simple metal surfaces - art. no. 035423

Self-consistent calculations of the energy-loss spectra of charged particle s moving near a plane-bounded free-electron gas are reported. Energy-loss p robabilities are obtained, within linear-response theory, from the knowledg e of the density-response function of the inhomogeneous electron system. Se lf-consistent single-particle wave functions and energies are obtained by s olving the Kohn-Sham equation of density-functional theory, and the electro nic response is then computed either in the random-phase approximation or w ith the use of an adiabatic local-density approximation. Special emphasis i s placed on the various contributions from collective and electron-hole exc itations to the energy loss of charged particles moving parallel with the s urface. The effect of the electronic selvage at a metal surface on the ener gy-loss spectra is also discussed, by comparing our full self-consistent ca lculations with those obtained for electron densities that drop abruptly to zero at the surface.