How close are the Slater and Becke-Roussel potentials in solids?
Fabien Tran1, Peter Blaha, Karlheinz Schwarz
1Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9/165-TC, A-1060 Vienna, Austria
Journal of Chemical Theory and Computation
|October 27, 2015
Summary
The Becke-Roussel potential approximates the Slater potential for electronic structure calculations. While often similar, differences in band gaps and magnetic properties for materials like Si, Ge, and NiO are significant.
Area of Science:
- Solid-state physics
- Computational materials science
- Quantum chemistry
Background:
- The Slater potential is derived from the exact exchange hole, crucial for accurate electronic structure calculations.
- The Becke-Roussel (BR) potential offers a computationally cheaper approximation to the Slater potential.
Purpose of the Study:
- To conduct a detailed comparison of the Slater and Becke-Roussel potentials when applied to solids.
- To evaluate the impact of using the BR potential as a substitute for the Slater potential in electronic structure approximations.
Main Methods:
- Comparative analysis of electronic structure calculations using both Slater and BR potentials.
- Examination of specific materials including silicon (Si), germanium (Ge), and nickel oxide (NiO).
Main Results:
- Generally, the Slater and BR potentials yield similar results for electronic structures in most solids.
- Marked differences in fundamental band gaps and magnetic properties were observed for Si, Ge, and NiO.
Conclusions:
- The discrepancies highlight that the BR potential is not universally interchangeable with the Slater potential, especially for specific materials.
- Care must be taken when employing the BR potential in approximations of the exact-exchange Kohn-Sham potential due to potential significant deviations.
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