Relaxation dynamics of C60

The relaxation dynamics of C 60 from high-energy isomers to Buckminsterfullerene is examined using a master equation approach. An exhaustive catalog of the C 60 fullerene isomers containing only five- and six-membered rings is combined with knowledge of the Stone-Wales rearrangements that connect all such isomers. Full geometry optimizations have been performed for all the minima and the transition states which connect them up to six Stone-Wales steps away from the global minimum. A density-functional tight-binding potential was employed to provide a quantum mechanical description of the bonding. The resulting picture of the potential energy landscape reveals a "weeping willow" structure which offers a clear explanation for the relatively long relaxation times observed experimentally. We also predict the most important transient local minima on the annealing pathway.