The Kß emission spectra of various calcium, titanium, chromium, manganese and iron compounds were investigated by means of the fluorescent method. The origin of the lines found experimentally is discussed, their energies are given and used to construct composite energy diagrams. The dependence of the level positions on the chemical bond is shown, and an extrapolation is carried out to determine the charge on the metal ions in the pure metal.
Koster, A. S., & Mendel, H. (1970). X-ray kβ emission spectra and energy levels of compounds of 3D-transition metals-II : non-oxidic compounds. Journal of Physics and Chemistry of Solids, 31(11), 2523-2530. https://doi.org/10.1016/0022-3697(70)90070-3