Based on electron-counting rules devised from adsorption on metal surfaces, one would expect the slope of the O/OH and OOH/OH LFESRs to be 2 and 1, respectively. All functionals deviate significantly from this expectation. For GGA functionals, this discrepancy is likely caused by the lack of a flexible solvent model. However, the much larger deviation for hybrid functionals cannot be dismissed so easily-indeed, such low slopes for the O/OH LFESR were seen to persist even under the application of an implicit solvent model in Ref 12. Therefore, hybrid functionals, in particular those with greater than 10% exact exchange, do not support the commonly accepted assumption that the O ligand forms a double bond to the catalyst, whereas the OOH and OH ligands form single bonds. Instead, these functionals predict that the M-O and M-OH bonds are rather similar in nature (this is reflected in the near-unity slope of the scaling relationship shown in Figure (a)), and that the M-OOH bond is weaker than the M-OH bond by about half (Figure (b)).