Momentum-density effects upon the electronic stopping of elemental solids

Treatment of electronic stopping via kinetic theory and the orbital local p lasma approximation is extended (from free-standing ordered slabs) to inclu de bulk crystalline targets, and hence probe their electron momentum distri bution. Sensitive computational issues, important for comparison with exper imental data, are addressed. A primary result is unambiguous first-principl es prediction of large gas-solid and film-solid differences in Li stopping. Previous predictions had involved semi-empirical determination of mean exc itation energies. Additionally, a stopping anisotropy that is separate from and much smaller than familiar channelling and related to the familiar Com pton-profile anisotropy is treated, apparently for the first time. Example calculations for hexagonal Li and graphite are given.