The core level alignment method was used to calculate the ionisation potential and electron affinity of ZnSb 2 O 6 . A slab-gap model was constructed using the PBE0 relaxed structure and a vacuum and slab thickness of 30 Å using the surfaxe code. The (110) termination was selected, which has been demonstrated to be the lowest energy surface for rutile SnO 2 . The planar average of the electrostatic potential was converged and calculated within surfaxe, and the plateau of this was taken to be the energy of the vacuum.