MOLECULAR-DYNAMICS STUDY OF THE STRUCTURES OF BCC AND FCC MODIFICATIONS FORMED IN CRYSTALLIZATION OF SUPERCOOLED SODIUM

In the molecular-dynamics model, crystallization occurs due to the pre sence of a bcc (in one case) or an fee nucleus. The bcc modification, having a lower internal energy, is assumed to be the main crystalline state of sodium. The difference Delta E in the energies of the stable bcc crystal and metastable fee crystal is twice lower than the differe nce Delta E between the bce crystal and the supercooled liquid. The id entification of the structures formed within this model was performed by the method of statistical geometry with the emphasis on the topolog y of the Voronoi polyhedra for these crystals.