MODEL ANGULAR DISTRIBUTION FUNCTIONS IN CA3, CA4 AND CA6 STRUCTURAL UNITS OF GLASSY SYSTEMS

Abstract

We have calculated model partial angular distribution functions (pADFs) in CA₃, CA₄ and CA₆ structural units, i.e. an equilateral triangle with three vertical anions, A, and a central cation, C, a regular tetrahedron with four vertical anions, A, and a central cation, C and a square bipyramid with six vertical anions, A, and a central cation, C. The model pADFs were calculated employing a simple Monte Carlo procedure: the ions were being shifted at random within 3D spheres of radius r with uniform probability density and the AAA, ACA and CAA angles were calculated for each random configuration. Repeating the calculation 10⁸ −10⁹ times produced smooth probability densities for the angles’ values. Conventional reference data so obtained can be applied to estimate the overall degree of deformation of the considered structural units in numerically simulated materials.