CRYSTALLINITY EFFECTS ON THE SURFACE OPTICAL-RESPONSE IN METALS - A PRELIMINARY CALCULATION

The beginning of a practical evaluation scheme for dynamic screening at the surface of a crystalline metal is developed. The derivation shows how band-structure effects on the d parameters may be calculated. Simplified versions of the basic equations are evaluated for a model of the (110) face of Li. Several features, absent from jellium models, are shown to make significant contributions. The theory is still too approximate for direct comparisons with experiment, but indicates a feasible path towards that goal.