Figure 3

Scaled density distance \(({\hat{D}}_{\rho })\) between the i-LDA and the exact system as a function of the impurities’ strength V for chains with 2, 4 and 6 impurities at the center. We keep the percentage of impurities fixed at 20% of the sites, so we have d = 10 (for 2 impurities), d = 20 (for 4 impurities) and d = 30 (for 6 impurities). For all cases n = 0.4, U = 4 and open boundary conditions.