Ab-initio calculations of one-dimensional band structures of mixed-stack molecular crystals

We present the first ab-initio calculation of one-dimensional band structures of two mixed-stack tetrathiafulvalene-p-benzoquinones derivatives: TTF-CA and TTF-2,5Cl2BQ. We discuss the intra-chain coupling and derive hopping parameters to be used in model calculations. Our calculations reveal that the dispersion differs qualitatively from existing model calculations. Implications of our findings on the relation between symmetry breaking and intermolecular charge transfer are discussed. © 1997 Elsevier Science Ltd.