Ekholm et al. report measurements of F1s RIXS at 694.6 eV. As clearly seen from the simulated spectra in FIG. , and suggested by Ekholm and coworkers also, this excitation involves both the |F1s -1 t 1 1u (π) and |F1s -1 t 1 1u (σ) core-excited states. We simulated RIXS from both these resonances separately which corresponds to three discrete core-excited states distinctly separated in energy for DFT-ROCIS computation (see FIG. ) and the RIXS spectra are plotted in FIG. . The RIXS experiment was also done at two more excitation energies, i.e. at 692.7 eV and 696.3 eV, which target the 6t 1u and 7t 1u respectively. We denote these two simulated resonances in FIG. as DFT-ROCIS(6t 1u ) for 6t 1u and DFT-ROCIS(7t 1u ) for 7t 1u . resonance considering a localized core-hole along with experimental spectrum obtained from Ref. . Three separate incidence wavelength was used in the experiment. Here we show the spectra computed at the |F1s -1 6t 1 1u and |F1s -1 7t 1 1u resonance. The simulated RIXS spectra(DFT-ROCIS(6t1u)) for |F1s -1 6t 1 1u matches the polarization dependence measured at the 692.7 eV and the simulated RIXS spectra(DFT-ROCIS(7t1u)) for |F1s -1 7t 1 1u matches the polarization dependence measured at the 696.3 eV. See FIG. in SI for TD-DFT/CAM-B3LYP simulated RIXS. The polarization dependence was computed using Equation 10 in one-electron picture, neglecting interference between intermediate states.The red spectra indicate spectra at horizontal polarization(χ = 0 0 ) and blue spectra represents vertical polarization (χ = 90 0 ).