On the Brillouin-Zone Integrations in Second-Order Many-Body Perturbation Calculations for Extended Systems of One-Dimensional Periodicity

The validity and accuracy of various ways of drastically reducing the number of k-points in the Brillouin zone integrations Occurring in second-order many-body perturbation calculations of one-dimensional solids has been investigated. The most promising approximation can recover correlation energies of polyethylene and polyacetylene within 1% of converged values at less than a tenth of usual computational cost. The quasi-particle energy bands have also been reproduced quantitatively with the same approximation. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 2953-2959, 2009