@article{18597,
  abstract     = {{We propose a new method for calculating optical defect levels and thermodynamic charge-transition levels of point defects in semiconductors, which includes quasiparticle corrections to the Kohn-Sham eigenvalues of density-functional theory. Its applicability is demonstrated for anion vacancies at the (110) surfaces of III–V semiconductors. We find the (+/0) charge-transition level to be 0.49 eV above the surface valence-band maximum for GaAs(110) and 0.82 eV for InP(110). The results show a clear improvement over the local-density approximation and agree closely with an experimental analysis.}},
  author       = {{Hedström, Magnus and Schindlmayr, Arno and Schwarz, Günther and Scheffler, Matthias}},
  issn         = {{1079-7114}},
  journal      = {{Physical Review Letters}},
  number       = {{22}},
  publisher    = {{American Physical Society}},
  title        = {{{Quasiparticle corrections to the electronic properties of anion vacancies at GaAs(110) and InP(110)}}},
  doi          = {{10.1103/PhysRevLett.97.226401}},
  volume       = {{97}},
  year         = {{2006}},
}

@article{18622,
  abstract     = {{We present a general procedure for obtaining progressively more accurate functional expressions for the electron self-energy by iterative solution of Hedin's coupled equations. The iterative process starting from Hartree theory, which gives rise to the GW approximation, is continued further, and an explicit formula for the vertex function from the second full cycle is given. Calculated excitation energies for a Hubbard Hamiltonian demonstrate the convergence of the iterative process and provide further strong justification for the GW approximation.}},
  author       = {{Schindlmayr, Arno and Godby, Rex William}},
  issn         = {{1079-7114}},
  journal      = {{Physical Review Letters}},
  number       = {{8}},
  pages        = {{1702--1705}},
  publisher    = {{American Physical Society}},
  title        = {{{Systematic vertex corrections through iterative solution of Hedin's equations beyond the GW approximation}}},
  doi          = {{10.1103/PhysRevLett.80.1702}},
  volume       = {{80}},
  year         = {{1998}},
}