The K-edge XAS spectra are obtained by designating the metal's 1s molecular orbital as the donor orbital and any unoccupied orbital as the acceptor orbital. We calculated 50 excited states, incorporating the Tamm-Dancoff approximation (TDA) and allowing for quadrupole contributions. All DFT and TDDFT calculations are performed in Orca v5.0.4. All restricted active space self-consistent field (RASSCF), restricted active space perturbation theory (RASPT2), multiconfigurational pair density functional theory (MC-PDFT) and restricted active space state interaction (RASSI) calculations are performed in OpenMolcas v23.10. In the RASSCF calculations for metal K pre-edge XANES calculation, the RAS1 subspace consists of 1s orbital of the metal. The RAS2 subspace contains the five 3d orbitals of the metal center and two ligand-based orbitals. Three additional 4dorbitals of the metal are also considered in the RAS2 subspace. However, for Mn[Cor]py, only one ligand-based orbital is considered while the other active space remains the same.