摘要

A package of FORTRAN subroutines is provided for the Brillouin zone (BZ) integration of the Green%26apos;s functions (GF) and spectral functions. The relevant weighting factors at sampling points in the BZ are evaluated to high precision with the help of the formulas for both the real and imaginary parts. The analytical properties of implemented expressions are discussed, and their range of validity is determined. The limiting cases when values at the tetrahedron corners coincide are worked out in terms of the finite difference quotients and replaced by the derivatives. The present numerical algorithms are developed for one-, two- and three-dimensional simplexes, with the potential ability of handling simplexes with higher dimensions as well. As an example, the results of computation the simple cubic lattice CF%26apos;s are presented. %26lt;br%26gt;Program summary %26lt;br%26gt;Program title: SimTet %26lt;br%26gt;Catalogue identifier: AEKF_v1_0 %26lt;br%26gt;Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEKF_v1_0.html %26lt;br%26gt;Program obtainable from: CPC Program Library, Queen%26apos;s University, Belfast, N. Ireland %26lt;br%26gt;Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html %26lt;br%26gt;No. of lines in distributed program, including test data, etc.: 3176 %26lt;br%26gt;No. of bytes in distributed program, including test data, etc.: 19 416 %26lt;br%26gt;Distribution format: tar.gz %26lt;br%26gt;Programming language: Fortran %26lt;br%26gt;Computer: Any computer with a Fortran compiler %26lt;br%26gt;Operating system: Unix, Linux, Windows %26lt;br%26gt;RAM: 512 Mbytes %26lt;br%26gt;Classification: 4.11, 7.3 %26lt;br%26gt;Nature of problem: The integration of the Green%26apos;s function over the Brillouin zone appears in the computations of many physical quantities in solid-state physics. %26lt;br%26gt;Solution method: The integral over the Brillouin zone is computed with the tetrahedron linear method. %26lt;br%26gt;The complex weights are generated with the novel algebraic formulas free of apparent singularities and well suited for automatic computations. %26lt;br%26gt;Running time: A few mu sec per integral.

  • 出版日期2012-2