For both the DFT and wavefunction-based methods, the pre-edge features are determined by calculating the intensity-weighted average energy (IWAE) of transitions within the pre-edge region of the XANES spectra. These spectra are produced by summing all chemically significant transitions, applying pseudo-Voigt broadening to the peaks at the transition energies. This broadening involves an amplitude corresponding to the calculated intensity and peak width (full width at half-maximum, FWHM) of 1.5 eV.