Density Functionals based on the mathematical structure of the strong-interaction limit of DFT

Electronic excited states in extreme limits via ensemble density functionals

“…To make matters worse, interesting excitations often involve strong correlations which, as in all flavors of DFT, remain an outstanding challenge for approximations based on EDFT. [15] It is therefore of enormous interest if advances in understanding the strictly correlated limit of ground state DFT [16][17][18][19][20][21] could be transferred to ensemble problems. Strikingly, the present work reveals that strict correlations actually makes the ensemble problem easier, via an additional constraint:…”

“…In doing so, we shall extend to excited states concepts and core results which have previously been worked out for pure ground states only. [16][17][18][19][20][21] These works can be understood as providing a generalization of the seminal work of Wigner [24,25] to inhomogeneous systems within DFT. Our current work completes the generalization to include excited inhomogeneous systems within EDFT.…”