First principles investigations of a "quasi-one-dimensional" charge-transfer molecular crystal:: TTF-2,5Cl2BQ

We performed first principles calculations using the projector augmented wave method in order to get a clear description at a microscopic level of the electronic distribution far from the transition for TTF-2,5Cl(2)BQ. Our calculations predict for the first time a low-symmetry structure (ground state) of this compound. We relate them to a simple tight-binding scheme which allows us to discuss the pertinence of the one-dimensional models used to study the phase transitions in this class of materials. Copyright (C) 1998 Elsevier Science B.V.