Intermolecular motion in solid C₇₀: A molecular dynamics simulation study

Abstract

The rotational and intermolecular translational dynamics in solid C70 is analyzed using the trajectories of a molecular dynamics simulation of state points in the cubic high-temperature phase, the rhombohedral partially ordered intermediate phase, and the fully ordered monoclinic low-temperature phase. The rotational dynamics in the cubic phase is found to be fast with correlation times of the order of 10 ps and modest anisotropy. The monoclinic phase is characterized by a libron band centered around 2 meV. The orientational dynamics in the rhombohedral phase is uniaxial. However, the velocity autocorrelation spectra for the intermediate phase resemble more closely the results for the high-temperature than the fully ordered phase. © 1994 American Chemical Society.