In Figure we show the time records of one of the three the α angle (see Figure ) in a standard MD lasting for 128 ns, i.e. using the same amount of total CPU time of the HREM simulations previously described. No abrupt changes of the angle are observed during the first 50 ns of simulation implying that no flipping of the two involved phenyl moieties has taken place during this time. In Figure we report the PMF with respect to the α angle obtained with standard MD simulations.