For the TD-DFT simulation of RIXS at the |F1s -1 6a 1 1g , |F1s -1 6/7t 1 1u and |F1s -1 2t 1 2g resonances, 17 doubly occupied valence orbitals, with omission of the 5a 1g orbital from the set of orbitals considered in Ekholm et al. , were taken as the orbital space to generate the valence excitation. One localized core F1s orbital was rotated into the selected orbital space, thus forming the combined doubly occupied donor space. The 11 lowest lying virtual orbitals were taken into the orbital sub-space. Hence, the sub-space TD-DFT calculation included (1+17) occupied orbitals and 11 unoccupied orbitals. It is worth mentioning here that in the DFT-ROCIS protocol all the orbitals described above were included, along with the additional 5a 1g orbital, i.e. (1+18) occupied orbitals and 13 unoccupied orbitals.