Single-atom approximation for Kβ-to-Kα x-ray intensity ratios in chemical compounds of 3d elements

The single-atom approximation for the K beta -to-K alpha x-ray intensity ratios for chemical compounds of 3d elements has been tested with the discrete-variational X alpha (DV-X alpha) molecular-orbital (MO) method. The effective numbers of electrons in each atomic shell are obtained with the DV-X alpha method and used to calculate the I(K beta)/I(K alpha) ratio in the single-atom approximation. The calculated results are in good agreement with the DV-X alpha MO values for octahedral symmetry, but systematically smaller for tetrahedral symmetry. The reason for this discrepancy is ascribed to be the K beta (2,5) component, which is appreciable in some compounds with the tetrahedral symmetry.