First-principles calculations of structural changes in B2O3 glass under pressure

Using first-principles calculations, we study pressure effects in B(2)O(3) glass up to 600 GPa and perform a detailed analysis of the densified structure. Below approximately 10 GPa, the glass structure deforms without the appearance of increased coordination numbers. At the same time, some of the BO(3) units lose planarity. At higher pressure, we find a gradual increase in fourfold coordinated B atoms. Above approximately 150 GPa, BO(5) and BO(6) polyhedra appear in the structure, and their proportion increases up to the highest studied pressure of 600 GPa. We propose that our analysis stimulate the search for high-density phases of B(2)O(3).