Prediction of the phase diagram of rigid ${\mathrm{C}}_{60}$ 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 ${\mathrm{C}}_{60}$ 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 ∼1800 K, which is sufficiently high that the ${\mathrm{C}}_{60}$ molecule may be unstable.