Quasiparticle calculations of semicore states in Si, Ge, and CdS

We investigate binding energies of semicore states in prototype semiconductors by quasiparticle calculations. Band-structure calculations within the local-density approximation and standard Gm quasiparticle calculations underestimate these energies systematically. Employing an extended GW approach we obtain very good agreement of calculated quasiparticle energies of semicore states in Si, Ge, and cubic CdS with experimental data. This is achieved by renormalizing the quasiparticle peaks in the spectrum and including plasmon-induced satellite structure in the Green's function.