Smearing scheme for finite-temperature electronic-structure calculations
(2002) Physical review. B, Condensed matter and materials physics — Vol. 65, n° 3, p. 035111:1-035111:6 (2002)
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- Abstract
- The use of energy-dependent occupation numbers in density-functional theory has two purposes: simulating the canonical ensemble for the electrons at nonzero temperature (Fermi-Dirac occupation numbers), and improving the convergence with respect to the number of electronic wave vectors sampling the Brillouin zone. We present a scheme which combines both, providing finite-temperature eigenstate occupations with an additional smearing to improve sampling convergence. After developing the formalism and extracting a correction formula for the free energy, we test them on a small system of metallic aluminum for temperatures under 3000 K. In this regime, the Fermi-Dirac smearing alone gives only a modest reduction in the number of wave vectors needed fur convergence. Our scheme reduces significantly the number of wave vectors, while preserving the correct physical temperature dependence.
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Verstraete, M. J., & Gonze, X. (2002). Smearing scheme for finite-temperature electronic-structure calculations. Physical review. B, Condensed matter and materials physics, 65(3), 035111:1-035111:6. https://doi.org/10.1103/PhysRevB.65.035111 (Original work published 2002)