A Molecular Dynamics Study of the Solid Phase Transition in Sulphur Hexafluoride Clusters

The structural phase transition occuring in SF6 clusters is simulated in a Molecular Dynamics calculation performed on 229- and 137-molecule models. The variation of the potential energy obtained by first cooling and then warming the models shows that the transition is spread over roughly 20 K and that the transformation is reversible. The temperature of the end of the transition increases from 95 K to 105 K when going from 137 to 229 molecules. These results are consistent with the previous calculations on a 512-molecule model.