Indeed, DFAs with minimal delocalization error have excellent predictions of IPs and EAs from the HOMO and LUMO of generalized Kohn-Sham calculations, comparable to the accuracy of GW approaches. In addition, the orbital energies above the LUMO and below the HOMO approximate the corresponding quasi-particle energies, with similar accuracy as the HOMO/LUMO for the IP/EA. This has been explored to describe accurately the excitation energies and conical intersections of molecular systems in the quasi-energy DFT approach based on ground-state generalized Kohn-Sham calculations. (2.2.16) Baerends : In relation to contributions (2.2.15) and (2.2.11), it should be stressed that it is very important to distinguish between the properties of, on the one hand, the exact (original) Kohn-Sham model of noninteracting electrons in a local potential such that the exact density is reproduced and, on the other hand, the currently popular DFAs -in particular, those of the generalized Kohn-Sham family with nonlocal potentials. The local Kohn-Sham potential is unique by application of the Hohenberg-Kohn theorem to the noninteracting electron system, and so are the orbitals and orbital energies.