Density functional theory calculations were primarily performed within the plane-wave periodic code vasp, which uses the projector augmented wave method to describe the interactions between valence and core states, details of which can be found in Table . A plane-wave energy cut-off of 500 eV was used for all calculations, and a 7 × 7 × 4 Γ-centred k-point mesh was employed. The PBE0 hybrid exchange correlation functional was used because it has been shown to accurately reproduce the band gap of rutile-structured SnO 2 . The static dielectric constant was calculated with density functional perturbation theory (DFPT) using the PBEsol functional. Effective masses and band structures were calculated and plotted using the sumo code. O F Al Zn Ga Sb 2s 2 2p 4 2s 2 2p 5 3s 2 3p 1 3d 10 4s 2 4s 2 4p 1 5s 2 5p 3