Computer Simulations of Liquid Silica: Water-like Thermodynamic and Dynamic Anomalies, and the Evidence for Polyamorphism

The qualitative similarities between water and silica have long been appreciated [1,2]. The molecular structure of both substances is dominated by tetrahedral bonding arrangements under ambient pressure, in both the liquid and the solid states. As a consequence, several of the low-pressure ice phases have isomorphic analogs among the crystalline phases of silica (e.g., ice Ih and tridymite). The similarities between water and silica also extend to the properties of the liquid and amorphous solid forms. Water and silica are both members of a small set of substances that exhibit a density maximum in the liquid phase [1,2].