Single-Particle Properties from Kohn-Sham Green's Functions
  An effective action approach to Kohn-Sham density functional theory is used to illustrate how the exact Green's function can be calculated in terms of the Kohn-Sham Green's function. An example based on Skyrme energy functionals shows that single-particle Kohn-Sham spectra can be improved by adding sources used to construct the energy functional. 
Anirban Bhattacharyya and R.J. Furnstahl