Quasiparticle electronic structure of copper in the GW approximation.

We show that the results of photoemission and inverse photoemission experiments on bulk copper can be quantitatively described within band-structure theory, with no evidence of effects beyond the single-quasiparticle approximation. The well-known discrepancies between the experimental band structure and the Kohn-Sham eigenvalues of density functional theory are almost completely corrected by self-energy effects. Exchange-correlation contributions to the self-energy arising from 3s and 3p core levels are shown to be crucial.