Self-energy and spectral function of Ce within theGWapproximation

To investigate how far the GW approximation can treat systems with strong on-site correlations, we perform calculations of the self-energies and spectral functions of alpha-and gamma-Ce within the GW approximation. For this strongly correlated material, the screened interaction exhibits a complex and rich structure which is attributed to strong particle-hole transitions involving localized 4f states. This structure in the screened interaction is carried over to the self-energy, which in turn yields spectral functions with multiple peaks. A satellite at around 5 eV above the Fermi level is formed, which is reminiscent of the experimentally observed upper Hubbard band, while the experimentally observed peak structure below the Fermi level at -2 eV and disappearance of the quasiparticle peak in the. phase are not reproduced. DOI: 10.1103/PhysRevB.86.245126