Valence electrons Energy dissipation 6 Approximation theory 4 Atomic physics 4 Electrons 4 Ion beams 4 Perturbation techniques 4 Targets 4 Ab-initio calculations 2 Atomic force microscopy 2 Atomic numbers 2 Atoms 2 Backscattering 2 Band structure 2 Binding energy 2 Binding sites 2 Carbon nanotubes 2 Cross section 2 Cross sections 2 Crystal atomic structure 2 Crystal impurities 2 Dielectric functions 2 Dielectric materials 2 Dielectric response 2 Dirac equations 2 Electron energy loss spectroscopy 2 Electron gas 2 Energy loss 2 Energy regions 2 Energy straggling 2