GWT approximation for electron self-energies in semiconductors and insulators
|Title||GWT approximation for electron self-energies in semiconductors and insulators|
|Publication Type||Palaiseau Article|
|Author Address|| |
DELSOLE, R (Reprint Author), UNIV PARIS 11,CTR EUROPEAN CALCUL ATOM & MOLEC,BATIMENT 506,F-91405 ORSAY,FRANCE. UNIV ROMA TOR VERGATA,DIPARTIMENTO FIS,I-00133 ROME,ITALY. ECOLE POLYTECH,CTR NATL RECH SCI,COMM ENERGIE ATOM,SOLIDES IRRADIES LAB,F-91128 PALAISEAU,FRANCE. UNIV CAMBRIDGE,CAVENDISH LAB,CAMBRIDGE CB3 0HE,ENGLAND.
|Del Sole, R, Reining, L, Godby, RW|
|Year of Publication||1994|
|Journal||Phys. Rev. B|
The widely used GW approximation for the self-energy operator of a system of interacting electrons may, in principle, be improved using an approximate vertex correction GAMMA. We estimate GAMMA using the local-density approximation. We report the results of a comparable series of GW calculations for the band structure of silicon, in which such a vertex correction is (i) excluded entirely, (ii) included only in the screened Coulomb interaction W, and (iii) included in both W and the expression for the self-energy. We also discuss the symmetry properties of the exact vertex correction and how they may be retained in further improvements.