Ab initio molecular dynamics study on the thermal dissociation of acetic acid

The potential of density functional theory (DFT/PW91)-based ab initio molecular dynamics (MD) method for a priori elucidation and direct simulation of chemical reaction without an empirical potential energy surface was tested for the unimolecular thermal dissociation of acetic acid. The accuracy of DFT calculations with PW91 and BLYP types of functionals for energy barriers was confirmed, and within a limited number (32) of trajectories, all three dissociation channels were identified. Internal rotations in acetic acid were found to facilitate H migration among functional groups, which played an important role in its dissociation.