From molecules to organic crystals: the contribution of quantum chemistry

Quantum chemistry is now able to provide a quantitative description of the topology of electron interactions in organic conductors. Beyond the one electron picture, the calculation of Coulomb repulsion interactions is also feasible. The refinement of the calculation tools now offers a deeper and consistent insight on the intra and intermolecular interactions in the materials, that do not suffer from the preconceptions that have plagued the extraction of phenomenological model Hamiltonians. VB models form the backbone of consistent extraction procedures. They can also reveal sizeable new electron coupling mechanisms such as the anion-cation pole-induced dipole interaction. (orig.)