We also investigate the impact of ligand field strength on the metal-oxo formation vs. HAT reaction energetics as reported in prior literature. We find that the spin state of the catalyst dictates how ligand field strength influences the reaction energetics. Consistent with prior work, in higher-spin states (IS and HS states), we generally observe that catalysts comprising weak-field oxygen-containing ligands exhibit favorable HAT energies at the expense of less favorable metaloxo formation energies (Supporting Information Figure ). In the LS state, the trends are reversed wherein catalysts with strong-field carbene or substituted isocyanide ligands have unfavorable DE(oxo) values but very favorable DE(HAT) energies (Supporting Information Figure ). We note that the diversity and size of our dataset leads to broad distributions of the metal- oxo formation and HAT reaction energetics for sets of catalysts with ligands of qualitatively similar field strength. Nonetheless, these trends are more pronounced for Fe catalysts than Ru catalysts, particularly in higher-spin states, which suggests a greater degree of tunability via modulating the ligand field in C-H activation reactivity for Fe catalysts.