BASIC MATRIX-ELEMENTS FOR LEVEL SHIFTS AND WIDTHS OF HYDROGENIC LEVELS IN ION-SURFACE INTERACTIONS

We present extensive studies of basic one-electron matrix elements inv olved in ion-metal surface scattering theory. Our method allows for th e convenient generation of matrix elements for high principal quantum numbers of hydrogenic projectile states and thus provides basic buildi ng blocks for the ab initio description of the interaction of highly c harged ions with surfaces. The matrix elements related to the energy s hifts can be evaluated for an arbitrary one-dimensional potential ther efore allowing for flexibility in the choice of model-perturbation pot entials. The transfer matrix elements between hydrogenic levels and co nduction-band states have been formerly evaluated for the special case of eigenfunctions to the step-function potential. We extend these cal culations to wave functions generated from an arbitrary one-dimensiona l surface potential and show applications to various surface potential s and hydrogenic levels.