Electronic states of interstitial ions in alkali halide crystals

Abstract

Semicontinuum and continuum models are used to treat the electronic states of interstitial ions and atoms in insulating crystals. The Hartree-Fock-Slater approximation is used to treat the internal structure of the ions, in cases where such structure exists. Three systems are considered, namely, Na 0 in Nal, the U 2 center in KCl, and Ca + in KCl. In the second case, our results are somewhat at variance with those of Schechter, and cast some doubt on the vacancy-centered model of the lowest excited state.