Crystallization Close to the Glass Transition: Dynamic heterogeneities do not precede crystallization

We address the question whether a crystallization event can be predicted based on observations
of the mobility distribution in a supersaturated melt. We have carried out computer simulations
of overcompressed suspensions of hard monodisperse ellipsoids and observed their crystallization
dynamics. The system was compressed very rapidly in order to reach the regime of slow, glass-like
dynamics. We nd that, although particle dynamics become sub-diffusive and the intermediate
scattering function clearly develops a shoulder, crystallization proceeds via the usual scenario: nucleation and growth for small supersaturations, spinodal decomposition for large supersaturations.
In particular, we compared the mobility of the particles in those regions where crystallization set
in with the mobility in the rest of the system. We did not find any signature in the dynamics
that pointed towards the imminent crystallization event.