Electron Structure and X‐Ray Absorption Spectra of Potassium Chloride II. Effect of a Core Hole in the Cluster Approach

Abstract X‐ray K‐absorption spectra of potassium and chlorine for 27‐atom clusters KCl 6 K 12 Cl 8 and ClK 6 Cl 12 K 8 are calculated in the framework of the scattered wave method. The spectra obtained for the ground state of the cluster are in good agreement with infinite crystal ones which are calculated by the APW method. The dimensions of the cluster representative for the description of the X‐ray photoionization process in solids are discussed. The influence of the ls‐hole potential on the spectrum shape is investigated in the cluster approach. A fair correlation between the theoretical and experimental spectra is obtained. It is shown that it is necessary to take into account the deep hole potential for a correct calculation of X‐ray absorption cross‐sections.