Quasiparticle properties in a density functional framework
  We propose a framework to construct the ground-state energy and density matrix of an N-electron system by solving selfconsistently a set of single-particle equations. The method can be viewed as a non-trivial extension of the Kohn-Sham scheme (which is embedded as a special case). It is based on separating the Green's function into a quasi-particle part and a background part, and expressing only the background part as a functional of the density matrix. The calculated single-particle energies and wave functions have a clear physical interpretation as quasiparticle energies and orbitals. 
D. Van Neck (1), S. Verdonck (1), G. Bonny (1), P.W. Ayers (2), M.   Waroquier (1) ((1) Laboratory of Theoretical Physics, G...