Solidlike-to-liquidlike transition in small clusters of C60 molecules or transition-metal atoms

Using Girifalco's potential, we pet-formed molecular dynamics (MD) simulations of (C-60)(7) that show, for the first time, that a small fullerene cluster with no nonsurface molecules can achieve a liquidlike state. This contrasts with earlier work on (C-60)(13), but parallels Sawada and Sugano's findings concerning small clusters of transition-metal atoms (TMAs). Repetition of Sawada and Sugano's MD simulations using longer runs showed that, as in the case of (C-60)(7), for seven-atom TMA clusters the solidlike-to-liquidlike transition is gradual and its completion is marked by a peak in the specific heat curve.