Nonequilibrium molecular dynamics calculations of homogeneous shear flow in two dimensions have been performed on soft disks close to the freezing transition. Simulations at discrete shear rates, ggr;dot;, reveal complex phase changes and dynamical behavior during extensive shear thinning and a difference in the values of the diagonal components of the pressure tensor. A shear thickening regime was also found near to ggr;dot;=10 but it had disappeared at ggr;dot;=50, in line with recent work by Woodcock. The calculations reveal that there is a change from an amorphous liquid structure at ggr;dot;=1.0 to a fluid microscopically layered along the stream lines at ggr;dot;=10 and higher shear rates. An intermediate twohyphen;phase region was observed at ggr;dot;=5 in which both amorphous and ordered phases coexist within the MD cell, containing 896 disks. In the ordered phase the particle dynamics are dominated by the imposed shear flow and can be reproduced in large part by simple models which exclude thermal motion. The time correlation functions are highly oscillatory which reflect well defined motion on a local distance scale. The soft disks spend most of their time trapped between similar disks in adjacent layers, in between rapid periods of lsquo;lsquo;freehyphen;flightrsquo;rsquo;. Instantaneous pictures of the high shear rate (ggr;dot;gsim;10) structure consequently show the presence of oscillating transitory strings of highly overlapping soft disks formed roughly perpendicular to those stably formed along the streamlines.
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