Potential energy surface of C6F6− radical anion

A successive symmetry reduction of the C6F6− radical anion along the active Jahn–Teller and pseudo-Jahn–Teller modes has been considered with ab initio calculations. Stationary points of the potential energy surface have been located and their types and interrelations determined. The energy values for stationary structures have been adjusted by MP2 calculations. The structures of C2v and D2 symmetry forming a pseudo-rotational surface are the lowest in energy. The pseudo-rotation includes six minima (C2v) and six transition states (D2). The corresponding barrier height has been estimated as 0.2 kcal/mol from MP2/6-31+G*//6-31+G* calculations.