Abstract
Soft X-ray absorption spectra of alkali halides exhibit prominent peaks near the ionization threshold of alkali core orbitals. These experimental features, generally attributed to highly localized excitations, confined within the first layer of nearest neighbours, have been treated both from an atomic or molecular point of view and from a band structure point of view. The relationship between these two representations is discussed for the case of the Li+K spectrum of LiF, recently treated by Kunz et al. (see abstr. A69104 of 1973) using a Hartree-Fock band calculation.