The role of hopping on transport above Tc in glycerol

Abstract

We present an analysis of atomistic MD simulations of glycerol that give evidence of two distinct dynamic states at short times in a realistic molecular liquid and show that these are associated with hopping at temperatures well above the melting temperature and the mode coupling critical temperature, Tc. We find that this hopping mode contributes significantly to transport, even at these high temperatures. The simulations support our previous interpretation of incoherent quasi-elastic neutron scattering (QENS) where we determined that, on a 1ps timescale and over a very wide temperature range, molecules are either highly confined or free to undergo relatively large scale motion.