## 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 for convergence, Our scheme reduces significantly the number of wave vectors, while preserving the correct physical temperature dependence.

Original language | English |
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Article number | 035111 |

Pages (from-to) | 351111-351116 |

Number of pages | 6 |

Journal | Physical Review B - Condensed Matter and Materials Physics |

Volume | 65 |

Issue number | 3 |

DOIs | |

Publication status | Published - 15 Jan 2002 |

Externally published | Yes |