LOCAL INVESTIGATION OF THE GLASS-TRANSITION - MOLECULAR-DYNAMICS AND VORONOI TESSELLATION

A model glass is studied by classical molecular dynamics and the Voron oi cells are determined at various times and temperatures. All their c haracteristics of physical interest are studied as a function of tempe rature. In particular, as temperature increases in the glass phase, th e fraction of 4- and 6-edged faces (encircling disclination defect lin es) increases at the cost of 5-edged faces. At the glass transition th is trend is reversed and a majority of pentagons is recovered in the l iquid phase. These results shed new light on the evolution of the loca l structure through the glass transition.