Development of empirical potentials for sodium borosilicate glass systems

New parameter values are proposed for the empirical potentials used to describe SiO₂-B₂O₃-Na₂O alkali borosilicate glass systems. They are based on Buckingham potentials, but include dependence between the fitting parameters and the glass chemical composition to improve the representation of the complex environment around the boron atoms. In particular, the boron anomaly (observed when the [Na₂O]/[B₂O₃] ratio varies) is correctly reproduced. The structural and mechanical properties of a wide range of glass compositions and of reedmergnerite crystals are correctly simulated: bond distances, mean angles, densities, elastic moduli. The deviations from the experimental values are small.