Glass Transition in Monoatomic Systems: Dilution of One Structure or Competition between Two Structures?

Properties of Voronoi polyhedra in several monoatomic glass-forming systems are discussed. They are compared to properties of a Kob–Andersen mixture. It is shown that two mechanisms of vitrification are possible: the blurring of Voronoi polyhedra and the formation of polyhedra of two different shapes. Both mechanisms reduce the crystal order in the system and the glass transition.