Comparison of ab initio molecular properties of EDO-TTF with the properties of the (EDO-TTF)2PF6 crystal

We performed ab initio quantum chemical calculations for the geometrical and electronic structure of the EDO-TTF (ethylenedioxy-tetrathiafulvalene) molecule using HF, CASSCF and DFT methods. We compare these in vacuo results with the properties of the (EDO-TTF)2PF6 crystal at near room temperature. We demonstrate that, by bending and charging the molecule in vacuum, the deformation that is thought to be the origin of charge ordering in this material is an inherent property of the EDO-TTF molecule. We further show that deformations can be readily made at ambient temperatures.

Intrinsic geometry of EDO-TTF (side view) and the HOMO and HOMO-1 molecular orbitals.32