The Coulomb potential, ψ, in which water's partial charges are accounted for explicitly in the mean charge density field differs qualitatively from the predictions of Gouy-Chapman theory. These differences arise due to the molecular nature of water and therefore signal a breakdown in the dielectric continuum assumption. 120 The primary differences are pronounced oscillations, due to molecular layering at the solid surface, and an overall interfacial potential drop ∆V ̸ = V ext , due to water's preference to orient with its hydrogens pointing toward the electrode under unbiased conditions. The qualitative details of this potential profile depend on the characteristics of the force field. However, a significant difference from Gouy-Chapman theory is very likely a general characteristic of all-atom systems.