Probing unoccupied and occupied Pu 5f states of PuO 2 : The calculated LFDFT Pu M 5 -edge CC-RIXS and VB-RIXS maps are shown in Figure and Figure respectively. Selected cross sections along the excitation and emission energy scales are shown in Figures and and represent the calculated HR-XANES and VB-RIXS spectra, respectively. The experimental HR-XANES and VB-RIXS spectra of PuO 2 are also shown in Figures and, respectively, for comparison. The calculated Pu M 5 -edge HR-XANES spectrum is in agreement with the experimental data in the energy region corresponding to the main X-ray absorption peak (Figure ). The experimental main absorption peak is characterized by a strong peak at 0 eV and a shoulder at slightly higher energy. Both the features are reproduced by the calculations. Note that the calculated CC-RIXS map exhibits lower emission satellite peaks that are better represented in logarithmic scale (cf. Figure ). These satellite features are in good agreement with the computed CC-RIXS map in Reference 44.