Published online by Cambridge University Press: 16 February 2011
Molecular dynamics simulation has been performed with dense systems of alkane-like chain molecules. Distribution of occupied and unoccupied space in the system was then evaluated by the technique of Voronoi tessellation of space and by enumeration of the cavities formed when hard spheres of diameter D were assumed placed on atomic centers. The distribution of cavity volumes is extremely broad and often exhibits a bimodal or trimodal character. These cavities change shape and size with time even at temperatures much below Tg.