Dynamic Heterogeneity In The Monoclinic Phase Of CCl4

NIRVANA B. CABALLERO; MARIANO ZURIAGA; MARCELO CARIGNANO; PABLO SERRA

JOURNAL OF PHYSICAL CHEMISTRY B

ACS Publications

Año: 2016 vol. 120 p. 860 - 865

1089-5647

Carbon tetrachloride (CCl$_4$) is one of the simplestcompounds having a translationally stable monoclinic phase whileexhibiting a rich rotational dynamics below 226 K. Recent nuclearquadrupolar resonance experiments revealed that the dynamics of CCl$_4$is similar to that of the other members of the isostructuralseries CBr$_{n}$Cl$_{4-n}$, suggesting thatthe universal relaxation features of canonical glasses such as$\alpha$- and $\beta$-relaxation are also present in non-glassformers. Using molecular dynamics simulations we studied therotational dynamics in the monoclinic phase of CCl$_4$.The molecules undergo $C3$ type jump-like rotations around each oneof the four C-Cl bonds. The rotational dynamics is very well describedwith a master equation using as the only input the rotational ratesmeasured from the simulated trajectories. It is found that theheterogeneous dynamics emerges from faster and slower modesassociated with different rotational axes, which have fixedorientations relative to the crystal and are distributedamong the four non-equivalent molecules of the unit cell.