THE MODELING COMPACTNESS COEFFICIENT FOR LATTICE OF CRISTOBALITE

Packing density (packing efficiency) is the ratio of the total volume occupied by the actual atoms in the crystal lattice, to its fullest volume. Various types of crystal lattices have different packing density of the atoms. For example, in a face-centered cubic lattice atoms occupy 74% of the total volume of the crystalline lattice, and interatomic intervals («pores») of 26%. In the body-centered cubic lattice of atoms occupy 68% of the total, and the «pores» of 32%. The packing efficiency of the lattice depends on the electronic structure of crystals and the nature of the relationship between their atoms. The packing density allows the calculation of such characteristics of the crystal structure as the internuclear distance and the lattice constant. Knowledge which makes it possible to visualize three-dimensional model of the unit cell of the crystal. Theoretical and numerical methods for calculating the packing density of crystals for the cubic symmetry are proposed in this article. Also, on the basis of these results, the technique of calculating the interatomic distances and comparing them with existing reference values. Efficiency and effectiveness of the methods is demonstrated by the crystal lattice type cristobalite.