LAUSR

Structural phases in crystal BEDT-TTF under the influence of doping molecules were studied. The system demonstrates the transition from a parallel aligned molecular phase (β-phase) to a new equilibrium state, where the molecules are rotated at a certain angle (α- or θ-phase). The precursor of this transition is the electrostatic and quadrupole interaction between BEDT-TTF and doping molecules. The modified potential of the Girifalco type is introduced, it depends on both intermolecular distance and the angle of the molecular rotation. It is found that the equilibrium distance between molecules in a stack increases and the deflection angle arises with an increase of the charge of doping molecules, which leads to new equilibrium states.