title: Correlation effects of π electrons on the band structures of conjugated polymers using the self-consistent GW approximation with vertex corrections.
abstract: Many-body perturbation theory is used to investigate the effect of π-electron correlations on the quasi-particle band structures of conjugated polymers at the level of the Pariser-Parr-Pople model. The self-consistent GW approximation with vertex corrections to both the self-energy and the polarization in Hedin's equations is employed in order to eliminate self-interaction errors and include the effects of electron-hole attraction in screening processes. The dynamic inverse dielectric function is constructed from the generalized plasmon-pole approximation with the static dressed polarization given by the coupled-perturbed Hartree-Fock equation. The bandgaps of trans-polyacetylene, trans-polyphenylenevinylene and poly(para)phenylene are calculated by both the Hartree-Fock and GW approximation, and a lowering of bandgaps due to electron correlations is found. We conclude that both dielectric screening and vertex corrections are important for calculating the quasi-particle bandgaps of conjugated polymers.
authors.affiliation: Department of Chemistry, Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan.
authors.forename: Yao-Wen
authors.initials: YW
authors.lastname: Chang
authors.forename: Bih-Yaw
authors.initials: BY
authors.lastname: Jin
mesh_terms: D004583:Electrons; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D011108:Polymers