Selective Orbital Imaging of Excited States with X-Ray Spectroscopy: The Example of alpha-MnS

Herein we show that nonresonant inelastic x-ray scattering involving an s core level is a powerful spectroscopic method to characterize the excited states of transition metal compounds. The spherical charge distribution of the s core hole allows the orientational dependence of the intensities of the various spectral features to produce a spatial charge image of the associated multiplet states in a straightforward manner, thereby facilitating the identification of their orbital character. In addition, the s core hole does not add an extra orbital angular momentum component to the multiplet structure so that the well-established Sugano-Tanabe-Kamimura diagrams can be used for the analysis of the spectra. For alpha-MnS we observe the spherical charge density corresponding to its high-spin 3d(5) ((6)A(1)) ground state configuration and we were able to selectively image its excited states and identify them as t(2g) (T-5(2)) and e(g) (E-5) with an energy splitting 10Dq of 0.78 eV.