We observe relatively low oxo formation barriers of 11 kcal/mol and 5 kcal/mol for DADLEC and LUSHOX04, respectively, indicating facile formation of the active metal-oxo species for C-H activation of methane (Figure ). We selected N2O as the oxidant for calculating reaction coordinates due to difficulties mapping out a reaction coordinate in which molecular O2 is split (i.e., with a co-reductant, as in enzyme catalysis, or via multiple metal centers ).