The absolute potential scale, U abs , can be shifted to the SHE scale, using the conversion U abs = U SHE + 4.44 eV, as recommended by Trasatti . The potential at zero charge, U P ZC , is linearly correlated to the electrode work function in the absence of the electrolyte . However, this correlation is empirical and it depends on the degree of orientation of surface water molecules as well as the electron density redistribution at the interface . Mills et al. assumed U P ZC as zero in their similar investigation . We consider U P ZC = Φ 0 +const. as hyperparameter, with Φ 0 = 5.3 eV as the experimentally measured work function of NiOOH , and evaluate a range of values from (-4.5,-3.5) eV for the constant term. This covers a range of (0.8, 1.8) V vs. SHE for U P ZC , in which NiOOH was reported to be stable in a pH range of 2 to 14 . A change in the surface dipole moment relative to the stoichiometric surface due to deprotonation and cation adsorption was obtained from the direct correlation with the corresponding work function shift ,