Free volumes and liquidlike clusters in soft-core dense liquids and glasses

With the particle configurations generated by molecular dynamics calculations for the soft-core system, free volumes of each particle are calculated in dense, supercooled liquids and glasses. These free volumes, the size distributions are used to divide the particles into two classes, the solidlike and liquidlike particles. The fraction p of the liquidlike particles and the connected liquidlike clusters with neighboring liquidlike particles are examined. Average cluster size and liquidlike neighbors are obtained as a function of p. It is shown that liquid–glass transition is associated with the decrease of p with increasing reduced density and the transition, is described by a type of percolation transition, which occurs at about pc?0.2 (critical concentration).