Effects of d-electrons in pseudopotential screened-exchange density functional calculations
We report a theoretical study on the role of shallow d states in the screened-exchange local density approximation (sX-LDA) band structure of binary semiconductor systems.We found that inaccurate pseudo-wavefunctions can lead to 1) an overestimation of the screened-exchange interaction betweenthe localized d states and the delocalized higher energy s and p states and 2) an underestimation of the screened-exchange interaction between the d states. The resulting sX-LDA band structures have substantially smaller band gaps compared with experiments. We correct the pseudo-wavefunctions of d states by including the semicore s and p states of the same shell in the valence states. The correction of pseudo-wavefunctions yields band gaps and d state binding energies in good agreement with experiments and the full potential linearized augmented plane wave sX-LDA calculations. Compared with the quasi-particle GW method, our sX-LDA results shows not only similar quality on the band gaps but also much better d state binding energies. Combined with its capability of ground state structure calculation, the sX-LDA is expected to be a valuable theoretical tool for the II-VI and III-V (especially the III-N) bulk semiconductors and nanostructure studies.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Computational Research Division
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 940403
- Report Number(s):
- LBNL-754E; JAPIAU; TRN: US200823%%805
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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