The initial Fe and Ru mononuclear octahedral metal-oxo geometries were constructed using molSimplify 107 with monodentate and macrocyclic ligand combinations adapted from prior work. From the optimized metal-oxo geometry, we functionalized the metal-oxo structure with a hydrogen atom to generate initial structures for the metal-hydroxo species and removed the oxo moiety to generate initial structures for the resting state, as done in prior work. Initial structures of the isopropanol-bound species were generated by adding an isopropyl group to the optimized metal-hydroxo structure (Supporting Information Figure ). The workflow of DFT calculations begins by optimizing the metal-oxo geometries in three spin states: low spin (LS), intermediate spin (IS), and high spin (HS), and calculations of subsequent intermediates are only attempted following successful calculations of prior intermediates while conserving the spin state. Thus, we go from an S = 0 (LS), 1 (IS), 2 (HS) metal-oxo to an S = 0 (LS), 1 (IS), 2 (HS) resting state and from an S = 1/2 (LS), 3/2 (IS), 5/2 (HS) metal-hydroxo to S = 0 (LS), 1 (IS), 2 (HS) isopropanolbound intermediate (Supporting Information Text S2).