The role of the attractive forces in a supercooled liquid

Abstract

Molecular Dynamics simulations of crystallization in a supercooled liquid of Lennard-Jones particles with different range of attractions shows that the inclusion of the attractive forces from the first, second and third coordination shell increases the trend to crystallize systematic. The bond-order $Q_6$ in the supercooled liquid is heterogeneously distributed with clusters of particles with relative high bond-order for a supercooled liquid, and a systematic increase of the extent of heterogeneity with increasing range of attractions. The onset of crystallization appears in such a cluster, which together explains the attractive forces influence on crystallization. The mean square displacement and self-diffusion constant exhibit the same dependence on the range of attractions in the dynamics and shows, that the attractive forces and the range of the forces plays an important role for bond-ordering, diffusion and for crystallization.