Fig. 7
From: Exact exchange-correlation potentials from ground-state electron densities
Nature and extent of electronic correlations in \({{\rm{H}}}_{2}\) molecules. A comparison of the exact exchange-correlation (\({v}_{{\rm{xc}}}\)) and the exchange-only (\({v}_{\text{x}}\)) potentials is provided for \({{\rm{H}}}_{2}\) molecules at three different bond lengths: (a) equilibrium bond length (\({{\rm{H}}}_{2}(eq)\)); (b) twice the equilibrium bond length (\({{\rm{H}}}_{2}(2eq)\)); (c) at dissociation (\({{\rm{H}}}_{2}(d)\)). The relative difference between \({v}_{{\rm{xc}}}\) and \({v}_{{\rm{x}}}\) indicates the nature and extent of electronic correlations. The correlations become stronger with bond stretching
