In both, the tetrahedral sites are Mn 2+ , and the octahedral sites are mixed Mn 3+/4+ . In the same way, H x Li y Co 3-δ O 4 (typically near H 0.37 Li 0.16 Co 2.66 O 4 ) forms a spinel structure with Co 2+ in the tetrahedral sites and with Co 3+ and Co 4+ on the octahedral sites. Li substitution into the base Co 3 O 4 structure promotes the presence of Co 4+ . These three compounds demonstrate how occupational disorder can promote the coexistence of three cation oxidation states.