At this point, we stress that the density constraint of eqn ( ) does not imply that, within the ensemble, interacting and Kohn-Sham densities match individually -in general, they do not. This can be seen in the regular ground-state limit of the theory, when the weights assigned to the excited states are equal to zero. This specific feature of ensemble DFT is reflected in the implicit weight-dependence of the Kohn- can be related to the concept of state-driven (SD) correlation. In the light of this analysis, the following decomposition may be used as a guideline for the development of ensemble correlation DFAs: