In an early investigation of ternary oxides, Shannon et al noted that edge-sharing Cd 2+ , In 3+ and Sn 4+ octahedra were a feature of common transparent conductors. Mizoguchi and Woodward built on this in 2004, investigating the necessity for edge-sharing octahedral connectivity when designing ntype TCOs. They found that edge-sharing is not a prerequisite, and corner sharing can also provide excellent dispersion of the conduction band, such as in BaSnO 3 . Interestingly, they identified some ternary oxides containing Sb(V) and Bi(V) which displayed reasonable curvature of the conduction band minimum (CBM), including tri-rutile zinc antimonate (ZnSb 2 O 6 ). It should be noted that group 15 cations in their highest oxidation states possess the same (n-1)d 10 ns 0 np 0 electronic structure as the cations in the common, successful TCOs.