Expanding upon the observations from the free energy landscapes wherein trends in metaloxo formation and HAT activation energies behave similarly to the reaction energetic trends, we use our set of six catalysts to investigate the validity of the metal-oxo formation and HAT Brønsted-Evans-Polanyi (BEP) relations that are widely used to accelerate catalyst discovery. Here, we consider the electronic barrier heights and energetics in the LS and IS states of the six Fe/Ru catalysts for which we characterize full reaction coordinates. For the metal-oxo formation step, in a given spin state, we define the activation energy, Ea(oxo), and the metal-oxo formation energy, DE(oxo), with respect to the oxidant-bound species (R) considered in the free energy landscapes. Despite the small dataset, the metal-oxo formation BEP appears to hold under our oxidant choice due to a strong correlation between Ea(oxo) and DE(oxo) (R 2 = 0.92) with a slope of 0.45 (Figure and Supporting Information Table ). Furthermore, the quality of fit is independent of the spin state, the metal identity or ligand field (Figure ). We note that among the six catalysts, the ammonia ligand is the most well-represented, yet the diversity in metal coordinating-atom identities is sufficient to establish a wide range of ligand field strengths (Supporting Information Figure ). Prior studies that use N2O as the oxidant show that the metaloxo formation BEP holds rather loosely and can widely vary as a function of metal-center out-ofplane distortions. We attribute the BEP relationship holding more strongly to our choice of oxidant because, unlike N2O that can distort through large-amplitude bending motions, 2,6- Next, we examine the HAT BEP to see if as strong a relation holds as in the case of metaloxo formation. In each spin state, we define the activation energy, Ea(HAT), and the HAT reaction energy, DE(HAT), with respect to the metal-oxo species. In our analysis, we consider HAT barriers and reaction energies for both the aand b-radical transfers for the Fe catalysts in the IS state since Fe catalysts may proceed via either HAT pathway, with the a-radical transfer being more dominant as discussed earlier (Supporting Information Table ). Contrary to the metal-oxo formation BEP, we find that the HAT BEP holds more loosely with a moderate correlation between Ea(HAT) and DE(HAT) (R 2 = 0.46) (Figure and Supporting Information Table ). In some cases, we observe negative Ea(HAT) values because it is defined relative to infinitely separated reactants.