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Analyzing Melts and Fluids from Ab Initio Molecular Dynamics Simulations with the UMD Package
Published on: September 17, 2021
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Ab initio interatomic potentials and the thermodynamic properties of fluids
Maryna Vlasiuk1, Richard J Sadus1
1Centre for Molecular Simulation, Swinburne University of Technology, P.O. Box 218, Hawthorn, Victoria 3122, Australia.
The Journal of Chemical Physics
|July 17, 2017
Summary
Accurate ab initio potentials improve thermodynamic predictions for argon and krypton. Three-body interactions enhance accuracy, especially for liquid phase properties, with the Marcelli-Wang-Sadus potential offering computational efficiency.
Area of Science:
- Computational physics and physical chemistry.
- Thermodynamics and statistical mechanics.
Background:
- Accurate prediction of thermodynamic properties is crucial for understanding fluid behavior.
- Ab initio interatomic potentials provide a fundamental basis for molecular simulations.
Purpose of the Study:
- To investigate the thermodynamic properties of argon and krypton using Monte Carlo simulations.
- To evaluate the impact of various two-body and three-body interatomic potentials on simulation accuracy.
Main Methods:
- Monte Carlo simulations were performed using accurate ab initio interatomic potentials.
- Calculations included isochoric and isobaric heat capacities, Joule-Thomson coefficient, and speed of sound.
- Results were validated against experimental or reference data.
Main Results:
- Accurate two-body ab initio potentials combined with three-body terms (Axilrod-Teller-Muto, Marcelli-Wang-Sadus) significantly improved thermodynamic predictions.
- Three-body interactions were found to lower heat capacities and increase the Joule-Thomson coefficient and speed of sound.
- The Marcelli-Wang-Sadus potential efficiently extends two-body ab initio potentials to liquid phase properties.
Conclusions:
- Accurate ab initio potentials, particularly when including three-body effects, are essential for reliable thermodynamic property predictions.
- The Marcelli-Wang-Sadus potential offers a computationally efficient method for incorporating these effects, especially for liquid phases.
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