Figure 2
From: Exact exchange-correlation potential of an ionic Hubbard model with a free surface
From the exact density to the exact KS potential.
Panel (a) and (b) show respectively the charge density and the KS potential for U = 6t at three different fillings, namely N = LB, N = LB ± 1. The inset of panel (a) presents a logarithmic plot of the density in the vacuum while the inset of panel (b) presents a schematic comparison between the spectrum of the Hubbard model and of the effective KS system for N = LB + 1 which we use below to qualitatively explain the peak in the main panel (b) appearing for this filling close to the surface. Other parameters are: w0 = 8t, δ = 0, LB = 6 and LV = 11.
