Identification of the ground spin state of catalytic intermediates in the radical rebound methane-to-methanol catalytic cycle provides insight into reactivity trends and determines whether the process is spin-allowed or spin-forbidden. We first evaluate the broad trends of spin splitting energies, ΔEI-L = E(IS)-E(LS), for the resting state, metal-oxo, metal-hydroxo, and methanolbound intermediates of codoped Mn, Fe, Co and Ru SACs (Figure ). ). Here, we focus on investigating Fe-based SACs due to their favorable reaction energetics.