Figure distinguishes Fe 2+ and Fe 3+ in different tetrahedral sites and shows the difference in electronic density of states between the two sites. The Fe 2+ site has a single high-energy occupied state as would be expected for a high-spin Fe 2+ d 6 cation. The Fe 3+ tetrahedral site density of states in the coupled structure matched that of the tetrahedral Fe in the non-coupled structure (Figure ) with no high-energy filled states in the spin-up channel. The distortion of the minority subset is therefore attributed to Fe 2+ and Mn 3+ Jahn-Teller distortion of the d 4 metal cations. This confirms the coupling nature of the subset of distorted structures allowing for some Mn 3+ and Fe 2+ to be present in the system.