nnp FY2014 Annual Report 01

Direct correspondence between the local morphology and microscopic dynamics in 2D aggregates.
(left panel) Probability of finding a particle at a distance 'r' and time 't=t*' from its position at 'r=0' and 't=0' is plotted for a compact crystalline configuration shown in the inset. As individual particles are always caged by their nearest neighbours, the probability is dominantly Gaussian (within cage) with an exponential tail (escape from cage). In the inset, the red dots represent instantaneous position of particles, say, at time 't*'; the background blue region represent the trajectory of all these particles from 't=0' upto 't*'.
(right panel) The same probability computed for particles in non-compact cluster shown in inset shows completely different behaviour. The distribution is largely exponential with a very small Gaussian near it origin. Directional bonding between particles is responsible for non-compact aggregates.