Related Experiment Video
Updated: Jun 30, 2026

Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions
Published on: June 13, 2015
Structure and speciation in hydrous silica melts. 1. Temperature and composition effects
Kelly E Anderson1, Marc M Hirschmann, J Ilja Siepmann
1Departments of Chemistry and of Chemical Engineering and Materials Science, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455-0431, USA.
This study used Monte Carlo simulations to explore hydrated liquid silica. Adding water significantly disrupts the silica network, altering its phase behavior and volume minimum properties.
Area of Science:
- Materials Science
- Geochemistry
- Computational Chemistry
Background:
- Liquid silica exhibits unique structural properties, including an anomalous volume minimum.
- Understanding the behavior of silica under high pressure and temperature is crucial for geological and materials science applications.
- The influence of water on silica's phase diagram and structure is not fully understood.
Purpose of the Study:
- To investigate the phase behavior of hydrated liquid silica using Monte Carlo simulations.
- To determine the effect of water mole fraction and temperature on the structural properties of liquid silica.
- To compare the disruptive effects of water and temperature on the silica network.
Main Methods:
- Monte Carlo simulations were performed in the isobaric-isothermal ensemble.
- Simulations utilized the Feuston-Garofalini potential.
- The study covered a range of temperatures (2000-9000 K) and water mole fractions (0.0-0.4) at a constant pressure of 1 GPa.
Main Results:
- The anomalous volume minimum of liquid silica persists up to a water mole fraction of approximately 0.267.
- Increasing water content lowers the temperature at which the volume minimum occurs.
- Water addition causes more significant disruption to the silica network than temperature alone.
- Simulations indicated very low concentrations of molecular water, with only about 1.2% of oxygen atoms bound to two hydrogen atoms at x w = 0.4 and T = 3000 K.
Conclusions:
- Water significantly alters the phase behavior and structural integrity of liquid silica.
- The presence of water is a more potent disruptor of the silica network than elevated temperatures.
- Further research is needed to fully elucidate the complex interactions within hydrated silica systems.
Related Concept Videos
Solid–Solid Solutions
Phase Transitions: Melting and Freezing
Strength and Heat of Hydration
The heat of hydration for each cement compound is significant; for instance, tricalcium aluminate (C3A) and...
Formation of Species
Aqueous Solutions and Heats of Hydration
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
Silica Gel Column Chromatography: Overview
Polar components tend to bind strongly to the silica gel, causing them to move slowly through the column. In contrast, nonpolar compounds...

