Showing papers by "Steven J. Plimpton published in 1997"
TL;DR: In this article, the self part of the van Hove correlation function was used to identify mobile particles in supercooled Lennard-Jones liquid, and these particles formed clusters whose sizes grow with decreasing temperature.
Abstract: We present the results of a molecular dynamics computer simulation study in which we investigate whether a supercooled Lennard-Jones liquid exhibits dynamical heterogeneities. We evaluate the non-Gaussian parameter for the self part of the van Hove correlation function and use it to identify {open_quotes}mobile{close_quotes} particles. We find that these particles form clusters whose sizes grow with decreasing temperature. We also find that the relaxation time of the mobile particles is significantly shorter than that of the average particle, and that this difference increases with decreasing temperature. {copyright} {ital 1997} {ital The American Physical Society}
829 citations
TL;DR: In this paper, the effect of intermolecular attraction on the blend structure and thermodynamics was examined. But the results were limited to a series of runs in which the attractive interactions were systematically varied from zero to the full Lennard-Jones value.
Abstract: Molecular dynamics (MD) simulations were carried out on a blend of 50 unit, pearl-necklace chains with the object of examining the effect of intermolecular attractions on the blend structure and thermodynamics. Repulsive interactions were imposed between intermolecular sites so that the effective hard core diameter of B type chains was 1.2 times that of the A type chains. Simulations were performed for a series of runs in which the attractive interactions were systematically varied from zero to the full Lennard-Jones value. Examination of the radial distribution functions revealed that the attractive interactions had very little effect on the blend structure up to the point of phase separation. Furthermore, we found that perturbation theory accurately predicted the changes in pressure associated with the variations in the attractive strengths.
9 citations