Allelectron Exact Exchange Treatment of Semiconductors Effect of Corevalence Interaction.pdfVIP

All-electron Exact Exchange Treatment of Semiconductors: Effect of Core-valence Interaction on Band-gap and d-band Position 5 ∗ 0 S. Sharma, J. K. Dewhurst, and C. Ambrosch-Draxl 0 2 Institut f¨ur Physik, Karl–Franzens–Universit¨at Graz, n a Universit¨atsplatz 5, A–8010 Graz, Austria J 7 (Dated: February 2, 2008) 1 Abstract ] i c Exact exchange (EXX) Kohn-Sham calculations within an all-electron full-potential method are s - l performed on a range of semiconductors and insulators (Ge, GaAs, CdS, Si, ZnS, C, BN, Ne, Ar, Kr r t m and Xe). We find that the band-gaps are not as close to experiment as those obtained from previous . t a pseudopotential EXX calculations. Full-potential band-gaps are also not significantly better for m - sp semiconductors than for insulators, as had been found for pseudopotentials. The locations of d n d-band states, determined using the full-potential EXX method, are in excellent agreement with o c [ experiment, irrespective of whether these states are core, semi-core or valence. We conclude that 1 the inclusion of the core-valence interaction is necessary for accurate determination of EXX Kohn- v 3 Sham band structures, indicating a possible deficiency in pseudopotential calculations. 5 3 1 PACS numbers: 71.15.Mb,71.10.-w,71.22.+i 0 5 0 / t a m - d n o c : v i X r a 1 Exact treatment of exchange within the Kohn-Sham (KS) formulation of density func- tional theory (DFT) has been one of the most interesting developments in