Impact of pressure on the structure of glass and its material properties

High pressures have a significant impact on the structure-related properties of glass, and are encountered in scenarios that range from fracture mechanics, where stress in the gigapascal regime is easily generated by sharp-contact loading, to the manufacture of permanently densified materials with tuned physical characteristics. Here, we consider the pressure-induced structural changes that occur in glass and show that, for oxide materials, the oxygen-packing fraction plays a key role in determining when these changes are likely to occur. Fivefold coordinated Si atoms appear as important intermediaries in the pressure-induced deformation of silica glass.