In these ab initio infrequent WT-MetaD simulations we used the distance between O OH and the C=O carbon as the CV. We deposited hills (initial height = 2.0E-3 Ha) every 100 steps, using a bias-factor of 50. A potential wall was imposed to limit CV values larger than 3 Å. The CV was monitored to determine the transition events, with a cutoff of < 1.4 Å for ⌧ on and of > 2.8 Å for ⌧ of f . Table reports the obtained data for the three dihedral angles.