IMPURITIES IN JELLIUM

Recently, x-ray absorption spectra of halide and rare-gas impurities in alkali metals have been measured. We study these systems by treating the alkali metal as jellium with a spherical cavity in which the halide or rare-gas impurity is placed. We use the density functional formalism with self-interaction corrections to find self-consistent solutions for the ground states and the states with a core hole. Specifically, we study F- in Na, F- in K, and Ne in K. We present charge densities and self-consistent potentials for these systems. We are able to find a self-consistent solution for both the ground state and the core hole state only for F- in Na. For F- in Na we calculate the exponent α0 which describes the many-body enhancement of the spectrum near the edge, and find that it confirms the experimental observation that the enhancement is small. We did not calculate the exponent α0 for Ne in K because we were unable to determine a self-consistent ground state for Ne in K. We consider one possible reason for our not finding a self-consistent ground state and discuss the possible relevance of this difficulty to understanding the large rounding seen in the x-ray edge spectra of rare-gas impurities in alkalis. © 1979 The American Physical Society.