Theory of the Auger spectra of Ca-Si compounds

The theoretical analysis of the Si L2,3VV Auger lineshapes of Ca-silides is performed on the basis of the electronic properties of the valence states computed by the LMTO-ASA method. In CaSi2 the spectrum is directly interpreted on the basis of the ground states valence density of states, while final states hole-hole repulsion is not negligible in Ca2Si. This correlation effect, which is present only when a final state is found in an s state, is due to the quasi-atomic configuration of the Si 3s states in the compound.