Prediction of the structures of clusters ofC60molecules using an atom-atom interaction potential

Using a full 60-site pairwise additive Lennard-Jones atom-atom potential to describe the interaction between ${\mathrm{C}}_{60}$ molecules, we computed the lowest-energy structures of $({\mathrm{C}}_{60}{)}_N$ clusters up to $N=20\mathrm{}$ and compared the results with predictions derived using Girifalco’s spherical potential. The atom-atom intermolecular potential provides the more realistic description of the ground-state structures of the fullerene clusters, including the relative orientation of the ${\mathrm{C}}_{60}$ molecules, but Girifalco’s potential affords a good qualitative description of certain features. In particular, Girifalco’s approximation is successful in predicting that $({\mathrm{C}}_{60}{)}_{13}$ is a highly stable, icosahedral cluster, and that a transition from icosahedral to decahedral structures occurs at a slightly larger cluster size.