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Updated: May 14, 2026
10:52
Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
Direct molecular dynamics simulation of liquid-solid phase equilibria for a three-component plasma
J Hughto1, C J Horowitz, A S Schneider
1Department of Physics and Nuclear Theory Center, Indiana University, Blooomington, Indiana 47405, USA. jhughto@astro.indiana.edu
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|February 2, 2013
Summary
Neutron-rich neon-22 impurities in white dwarf stars do not significantly alter carbon-oxygen freezing. However, simulations show lower melting temperatures than predicted, indicating issues with current models for multicomponent mixtures.
Area of Science:
- * Astrophysics
- * Computational Physics
- * Materials Science
Background:
- * Carbon-oxygen white dwarfs are key astrophysical objects.
- * Neutron-rich isotope ²²Ne is a potential impurity affecting stellar evolution.
- * Understanding phase transitions in these dense stellar interiors is crucial.
Purpose of the Study:
- * To investigate the influence of ²²Ne on the liquid-solid phase equilibria in carbon-oxygen-neon white dwarf interiors.
- * To compare simulation results with existing theoretical models.
Main Methods:
- * Employed molecular dynamics (MD) simulations to model carbon-oxygen-neon systems.
- * Utilized a bond angle metric to identify distinct liquid, solid, and interface regions.
- * Analyzed the composition of coexisting liquid and solid phases.
Main Results:
- * MD simulations showed good agreement with the semianalytic model for phase composition.
- * Trace amounts of ²²Ne did not significantly alter the chemical separation of carbon and oxygen.
- * Systematically lower melting temperatures were observed in MD simulations compared to the semianalytic model, particularly with increasing impurity parameter Q_imp.
Conclusions:
- * Small concentrations of ²²Ne are unlikely to qualitatively change the freezing process in white dwarf interiors.
- * The discrepancy in melting temperatures suggests limitations in current models for multicomponent solid mixtures, specifically the linear mixing rule for free energy corrections.
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