First-principles characterization of the electronic structure of the molecular superconductor β-(BEDT-TTF)2IBr2 -: art. no. 180505

The electronic structure of the molecular superconductor beta-(BEDT-TTF)(2)IBr2 has been studied by means of first-principles density functional calculations. The calculated transverse cross section of the Fermi surface is in excellent agreement with that reconstructed from magnetoresistance measurements. It is shown that the cylindrical Fermi surface exhibits warping (the dispersion along the interlayer direction is of the order of 0.8-1.7 % of the dispersion in the conducting plane) and that it does not contain any additional small pocket. These features provide support for a recent proposal concerning the much debated question of the origin of the slow magnetoresistance oscillations exhibited by this material.