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Published on: October 12, 2019
Accurate quasiparticle spectra from self-consistent GW calculations with vertex corrections
M Shishkin1, M Marsman, G Kresse
1Faculty of Physics, Universität Wien and Center for Computational Materials Science, Sensengasse 8/12, A-1090 Wien, Austria.
Physical Review Letters
|February 1, 2008
Summary
Accurate band gap calculations for semiconductors and insulators require including electron-hole interactions. Self-consistent GW calculations with vertex corrections yield band gaps within a few percent of experimental values.
Area of Science:
- Condensed matter physics
- Materials science
- Quantum chemistry
Background:
- Accurate prediction of electronic band gaps is crucial for understanding and designing materials.
- Traditional methods often struggle with accurately capturing electron-hole interactions, impacting band gap predictions.
Purpose of the Study:
- To investigate the necessity of including electron-hole interactions in self-consistent GW calculations for accurate band gap prediction.
- To evaluate the impact of vertex corrections on band gap accuracy across various materials.
Main Methods:
- Performed self-consistent GW (Green's function) calculations.
- Focused on the quasiparticle part of the Green's function G.
- Incorporated an effective nonlocal exchange-correlation kernel to model electron-hole attraction.
- Applied vertex corrections in W (W stands for screened Coulomb interaction).
Main Results:
- Self-consistent GW calculations are demonstrated for a diverse range of materials, including small-gap semiconductors and large-gap insulators.
- The inclusion of attractive electron-hole interaction is shown to be essential for accurate band gap determination.
- Accounting for these interactions via vertex corrections in W leads to band gaps within a few percent of experimental values.
Conclusions:
- Self-consistent GW calculations, when properly accounting for electron-hole interactions through vertex corrections, provide highly accurate band gaps.
- This approach offers a reliable method for predicting electronic properties of semiconductors and insulators.
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