$L_{2,3}{M}_{4,5}X$ Auger electron spectra of ${\mathrm{Br}}_2$ and Kr: Anomalous $L_2{M}_{2,3}{M}_{4,5}$ spectra

High-resolution $L_{2,3}{M}_{2,3}{M}_{4,5}$ and $L_{2,3}{M}_{4,5}{M}_{4,5}$ Auger electron spectra from ${\mathrm{Br}}_2$ and Kr have been measured using electron-beam excitation. The spectra have been decomposed into their components and interpreted by comparison with calculated energies and intensities. The theoretical calculations have been carried out in the mixed coupling scheme applying $\mathrm{jj}$ coupling for the initial state and intermediate coupling for the final state of the transition. Good agreement between the calculated and experimental results has been found for the $L_{2,3}{M}_{4,5}{M}_{4,5}$ and $L_3{M}_{2,3}{M}_{4,5}$ spectra of both bromine and krypton. There is, however, noticeable disagreement between theory and experiment for the $L_2{M}_{2,3}{M}_{4,5}$ spectra. The structure for the high-energy group is unusual and its intensity is anomalously low; a similar pattern is also seen for gallium, germanium, and arsenic.