The differences between ψ and φ are especially apparent when V ext = 0. In that case, Ψ GC predicts a featureless profile, which is similarly captured by φ. However, even under unbiased conditions, ψ predicts a non-trivial interfacial potential profile. This unbiased profile highlights the degree to which water's molecular nature can affect the interfacial electrostatic environment. It is interesting to consider what role, if any, the solvent dielectric plays in determining the shape of the interfacial potential profile and its associated electric fields. From the comparison between ψ and φ we can conclude that several significant features are lost in going from an atomistic description of the solvent to a dielectric continuum approximation.