Analogy of the slow dynamics between the supercooled liquid and supercooled plastic crystal states of difluorotetrachloroethane

Slow dynamics of difluorotetrachloroethane in both supercooled plastic crystal and supercooled liquid states have been investigated with molecular dynamics simulations. The temperature and wave-vector dependence of collective dynamics in both states are probed using coherent dynamical scattering functions S(Q,t). Our results confirm the strong analogy between molecular liquids and plastic crystals for which alpha-relaxation times and nonergodicity parameters are controlled by the nontrivial static correlations S(Q), as predicted by the mode coupling theory.