Related Experiment Video
Updated: Aug 14, 2026

High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems
Published on: January 24, 2014
Computer simulations of liquid silica: equation of state and liquid-liquid phase transition
I Saika-Voivod1, F Sciortino, P H Poole
1Department Of Applied Mathematics, University of Western Ontario, London, Canada.
Abstract:
We conduct extensive molecular dynamics computer simulations of two models for liquid silica [the model of Woodcock, Angell and Cheeseman, J. Phys. Chem. 65, 1565 (1976); and that of van Beest, Kramer, and van Santen, Phys. Rev. Lett. 64, 1955 (1990)] to determine their thermodynamic properties at low temperature T across a wide density range. We find for both models a wide range of states in which isochores of the potential energy U are a linear function of T(3/5), as recently proposed for simple liquids [Rosenfeld and P. Tarazona, Mol. Phys. 95, 141 (1998)]. We exploit this behavior to fit an accurate equation of state to our thermodynamic data. Extrapolation of this equation of state to low T predicts the occurrence of a liquid-liquid phase transition for both models. We conduct simulations in the region of the predicted phase transition, and confirm its existence by direct observation of phase separating droplets of atoms with distinct local density and coordination environments.
Related Concept Videos
Phase Diagrams
Phase Diagram
Phase Transitions
Phase Diagram
Two Components: Liquid–Liquid Systems
Solid–Solid Solutions

