Simulations of XA spectra: The XA spectra were computed at the DFT-ROCIS/B3LYP and TD-DFT levels of theory at the optimized geometry. Both the DFT-ROCIS and TD-DFT modules in the ORCA package enable the utilization of the orbital selection window to consider only excitation from the core orbitals to the unoccupied orbitals. The core-hole lifetime broadening (Γ) of F1s core-excited states were estimated to be about 0.194 eV , though with this broadening computed spectral lines have narrower peaks as compared to experiments due to neglect of vibrational broadening and experimental broadening. The discrete vertical excitations produced by DFT-ROCIS and TD-DFT were convoluted with a Voigt profile with Lorentzian fullwidth half-maximum (FWHM) of 0.4 eV and a Gaussian FWHM of 0.3 eV.