Electron-electron interactions and the bandwidth of metals

Abstract

A calculation is presented of the self-energy of an electron from the screened exchange energy. Vertex corrections are included. They have a large effect upon the predictions of the width of the occupied energy bands. For aluminum the band-width is predicted to be 0.7 eV wider in the GW approximation compared to GW\ensuremath{\Gamma} which includes vertex corrections. Results using the GW\ensuremath{\Gamma} approximation are similar to those of the random-phase approximation.