Band convergence and linearization error correction of all-electron GW calculations: The extreme case of zinc oxide

Abstract

Recently, Shih et al. [Phys. Rev. Lett. 105, 146401 (2010)] published a theoretical band gap for wurtzite ZnO, calculated with the non-selfconsistent GW approximation, that agreed surprisingly well with experiment while deviating strongly from previous studies. They showed that a very large number of empty bands is necessary to converge the gap. We reexamine the GW calculation with the full-potential linearized augmented-plane-wave method and find that even with 3000 bands the band gap is not completely converged. A hyperbolical fit is used to extrapolate to infinite bands. Furthermore, we eliminate the linearization error for high-lying states with local orbitals. In fact, our calculated band gap is considerably larger than in previous studies, but somewhat smaller than that of Shih et al..

4 pages, 2 figures

References in corpus (4)

• Quasiparticle band structure based on a generalized Kohn-Sham scheme
• Efficient implementation of the GW approximation within the all-electron FLAPW method
• Elimination of the linearization error in GW calculations based on the linearized augmented-plane-wave method
• Local exact exchange potentials within the all-electron FLAPW method and a comparison with pseudopotential results