F eb 2 01 6 Dynamic Heterogeneity In The Monoclinic Phase Of CCl 4

Carbon tetrachloride (CCl 4) is one of the simplest compounds having a translationally s table monoclinic phase while exhibiting a rich rotational dyn amics below 226 K. Recent nuclear quadrupolar resonance (NQR) experiments revealed that the dynamics of CCl 4 is similar to that of the other members of the isostructural series CBr n l4−n, suggesting that the universal relaxation features of canonical glasses such as αand β -relaxation are also present in non-glass formers. Using molecular dynamics (MD) simulati ons we studied the rotational dynamics in the monoclinic phase of CCl 4. The molecules undergo C3 type jump-like rotations around each one of the four C-Cl bonds. The rotational dynami cs is very well described with a master equation using as the only input the rotational rate s measured from the simulated trajectories. It is found that the heterogeneous dynamics emer ges f om faster and slower modes associated with different rotational axes, which have fixed orientations relative to the crystal and are distributed among the four non-equivalent molecule s of the unit cell.