The C SC needs to account for both the SCR and surface effects. Therefore, the equivalence of grand canonical and canonical ensemble methods cannot be established by interpolating to the infinite surface size limit in the surface xy-plane only but one also needs to interpolate to the infinite slab thickness limit in the z-direction to capture the capacitive contributions in this direction. Indeed, our recent work shows that four-layer metallic slabs are sufficient for modeling metallic electrodes whereas a SCE requires a much thicker slab to exhibit convergence. In general, one needs to account for the influence of both the surface/polaronic states (C SS ) as well as the SCR (C SCR ) contributions on the semiconductor capacitance (C SC )