Comment on "Configuration Interaction in the X-Ray Photoelectron Spectra of Alkali Halides"

Recently obtained data on doubly ionized Rb in the free state indicate that the satellite of the $\mathrm{Rb}\mathrm{}\left(4s\right)\mathrm{}$ resonance in the photoelectron spectra of RbF and RbCl is primarily due to a $4{s }^{2}4{p }^{4}4d {}_{}{}^2{}_{}{}^{}S$ final state rather than a $4{s }^{2}4{p }^{4}5s {}_{}{}^2{}_{}{}^{}S$ one. For the potassium salts, the satellite of the $\mathrm{K}\mathrm{}\left(3s\right)\mathrm{}$ resonance is most likely due to a $3{s }^{2}3{p }^{4}3d {}_{}{}^2{}_{}{}^{}S$ final state. The absence of a satellite for the $\mathrm{Na}\mathrm{}\left(2s\right)\mathrm{}$ resonance for the sodium salt is due to the nonexistence of $2d$ electrons.