https://doi.org/10.1140/epjb/e2007-00110-y
Spectral broadening due to long-range Coulomb interactions in the molecular metal TTF-TCNQ
1
Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
2
Institut für Festkörperforschung, Forschungzentrum Jülich, 52425 Jülich, Germany
3
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
4
Paul-Scherrer-Institut, WHGA/123, 5232 Villigen PSI, Switzerland
Corresponding author: a E.Koch@fz-juelich.de
Received:
25
January
2007
Published online:
27
April
2007
We employ density-functional theory to calculate realistic parameters for an extended Hubbard model of the molecular metal TTF-TCNQ. Considering both intra- and intermolecular screening in the crystal, we confirm the importance of the suspected longer-range Coulomb interactions along the molecular stacks, as well as inter-stack coupling. Contrary to past belief, these terms do not lead to the formation of a Wigner lattice, but simply broaden the spectral function.
PACS: 71.10.Fd – Lattice fermion models (Hubbard model, etc.) / 71.15.-m – Methods of electronic structure calculations / 71.10.Pm – Fermions in reduced dimensions (anyons, composite fermions, Luttinger liquid, etc.) / 79.60.Fr – Polymers; organic compounds
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2007
