Coulomb parameters and photoemission for the molecular metal TTF-TCNQ
  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 find significant longer-range Coulomb interactions along the molecular stacks, as well as inter-stack coupling. We show that the long-range Coulomb term of the extended Hubbard model leads to a broadening of the spectral density, likely resolving the problems with the interpretation of photoemission experiments using a simple Hubbard model only. 
Laura Cano-Cort\'es, Andreas Dolfen, Jaime Merino, J\"org Behler,   Bernard Delley, Karsten Reuter, and Erik Koch