Topology of planar corner-sharing network in B₂O₃ glass at intermediate range

B2O3 glass is a non-tetrahedral network-forming glass whose structure consists of boroxol rings that cannot form in crystalline phases under ambient conditions.In this study, a three-dimensional structural model of B2O3 glass containing a large fraction of boroxol rings (~80%) was successfully constructed by reverse Monte Carlo (RMC) modeling on the basis of high-energy X-ray diffraction data.This achievement is notable given that maintaining such a large fraction of boroxol rings has traditionally been considered difficult in conventional RMC modeling.Analyses of coordination number, bond angle distributions, and ring size distribution confirmed that the boroxol rings were well preserved in the model.The ring size distribution and persistence diagram revealed that B2O3 glass contains a large fraction of boroxol rings and a small fraction of larger rings with exceptionally high topological order, compared with typical tetrahedral network-forming glasses such as SiO glass.Our modeling and topological analysis can be extended to various B2O3-based glasses to provide a firm basis for understanding their physicochemical and structural properties at the atomic level.