A similar variation presented in the very weakly bound NiP(OOH), with GGA functionals preferring a configuration with an outward-facing hydrogen and the remaining functionals predicting hydrogen bond donation to the porphyrin nitrogen (Figure (d). Finally, the MP(O) intermediates showed moderate variations of about 0.1 Å depending on the functional used. On the whole, M-O bondlengths tend to correlate well within rungs of Jacob's ladder (Figure (b), even though most intermediates involved in electrocatalysis were fairly robust to changes in functional. Functional type and amount of exact exchange also correlated well with the amount that metal atoms were displaced from the porphyrin plane (Figure ) but less so with other geometrical parameters like metal-nitrogen bond lengths and the degree of ruffling and saddling of the macrocycle (Figures and).