A structural model for prototypical fluorozirconate glass

Existing interpretations of structural data and computer simulation results for binary BaF₂-ZrF₄ glasses are reviewed. Detailed comparisons of X-ray scattering results and new simulation results are made to determine the important structural features that a suitable model should be able to reproduce. A bipolyhedral module-based model for the glass which satisfies these constraints is then described and proposed as an idealization of the BaF₂-2ZrF₄ glass structure. Generalizations to other compositions and densities are considered. Key relationships to, and differences from, the bipolyhedral Zr₂F₁₂ ^4- module-based layer lattice recently determined for β-BaZr₂ F₁₀ are examined. The model is used as a basis for discussion of optical properties and crystallization kinetics.