Quasiparticle properties in a density-functional framework

D. Van Neck, S. Verdonck, G. Bonny, P.W. Ayers, M. Waroquier
Physical Review A
74 (4), 042501


We propose a framework to construct the ground-state energy and density matrix of an N-electron system by solving a self-consistent set of single-particle equations. The method can be viewed as a nontrivial extension of the Kohn-Sham scheme (which is embedded as a special case). It is based on separating the Green’s function into a quasiparticle 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.