Prediction of the phase diagram of rigid C60 molecules

An integral-equation approach combined with molecular dynamics simulations based on the Girifalco spherical intermolecular potential has been used to predict the phase diagram for rigid C60 molecules. The boundary of the liquid-vapor coexistence region and the location of freezing and melting lines have been sketched out. The liquid phase is only observed in a very narrow temperature range compared with atomic systems (e.g., the rare gases). Unfortunately, the dense fluid is predicted to exist above about 1800 K, which is sufficiently high that the C60 molecule may be unstable. (Author (revised))