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Citation: A. Fraile, S. Cuesta-López, A. Caro, D. Schwen, and J. Manuel Perlado (2014), "Interatomic potential for the compound-forming Li-Pb liquid alloy", Journal of Nuclear Materials 448(1–3), 103–108. DOI: 10.1016/j.jnucmat.2014.01.037.Abstract: Atomistic simulations of liquid alloys face the challenge of correctly modeling basic thermodynamic properties. In this work we present an interatomic potential for this system, as well as a study of physical properties of Li-Pb alloys. Despite the complexity due to Li-Pb being a compound forming system where charge transfer is expected, we show here how the empirical EAM formalism is able to satisfactorily describe several physical properties in a wide range of Li concentration. Application of our potential to Li-Pb eutectic allows us to correctly predict many physical properties observed experimentally and calculated with ab initio techniques, providing in this way a potential suitable for future studies in the context of tritium breeder blanket designs in Fusion technology.Citation: A. Fraile, and T. Polcar (2020), "Volume and pressure of helium bubbles inside liquid Pb16Li. A molecular dynamics study", Nuclear Fusion 60(4), 046018. DOI: 10.1088/1741-4326/ab73c2.Abstract: The behaviour of helium impurities inside metals has been well studied in the last 30 years, however, little attention has been devoted to helium atoms inside liquid metals. Here we have investigated the nucleation and coalescence processes of helium atoms inside liquid eutectic lithium-lead alloys using atomistic simulations. Several key findings regarding He bubbles inside liquid PbLi eutectic are presented. The radius versus the number of atoms has been calculated in the temperature range 600-1000 K. The trend can be fitted and likely extrapolated to larger bubbles (micrometer size). The value of thermal expansion of He bubbles is given as well and compared to the thermal expansion of bulk He. The pressure inside He bubbles has been calculated as a function of bubble size. Finally, the importance of accurate interatomic potentials for the He-metal interaction is discussed.
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LAMMPS pair_style eam/cd (2014--Fraile-A--Pb-Li--LAMMPS--ipr1)
Implementation Information
Diatom Energy vs. Interatomic Spacing
Plots of the potential energy vs interatomic spacing, r, are shown below for all diatom sets associated with the interatomic potential. This calculation provides insights into the functional form of the potential's two-body interactions. A system consisting of only two atoms is created, and the potential energy is evaluated for the atoms separated by 0.02 Å <= r <= 6.0> Å in intervals of 0.02 Å. Two plots are shown: one for the "standard" interaction distance range, and one for small values of r. The small r plot is useful for determining whether the potential is suitable for radiation studies.
The calculation method used is available as the iprPy diatom_scan calculation method.
Clicking on the image of a plot will open an interactive version of it in a new tab. The underlying data for the plots can be downloaded by clicking on the links above each plot.
Notes and Disclaimers:
- These values are meant to be guidelines for comparing potentials, not the absolute values for any potential's properties. Values listed here may change if the calculation methods are updated due to improvements/corrections. Variations in the values may occur for variations in calculation methods, simulation software and implementations of the interatomic potentials.
- As this calculation only involves two atoms, it neglects any multi-body interactions that may be important in molecules, liquids and crystals.
- NIST disclaimer
Version Information:
- 2019-11-14. Maximum value range on the shortrange plots are now limited to "expected" levels as details are otherwise lost.
- 2019-08-07. Plots added.
Click on plot to load interactive version
Click on plot to load interactive version
Cohesive Energy vs. Interatomic Spacing
Plots of potential energy vs interatomic spacing, r, are shown below for a number of crystal structures. The structures are generated based on the ideal atomic positions and b/a and c/a lattice parameter ratios for a given crystal prototype. The size of the system is then uniformly scaled, and the energy calculated without relaxing the system. To obtain these plots, values of r are evaluated every 0.02 Å up to 6 Å.
The calculation method used is available as the iprPy E_vs_r_scan calculation method.
Clicking on the image of a plot will open an interactive version of it in a new tab. The underlying data for the plots can be downloaded by clicking on the links above each plot.
Notes and Disclaimers:
- These values are meant to be guidelines for comparing potentials, not the absolute values for any potential's properties. Values listed here may change if the calculation methods are updated due to improvements/corrections. Variations in the values may occur for variations in calculation methods, simulation software and implementations of the interatomic potentials.
- The minima identified by this calculation do not guarantee that the associated crystal structures will be stable since no relaxation is performed.
- NIST disclaimer
Version Information:
- 2020-12-18. Descriptions, tables and plots updated to reflect that the energy values are the measuredper atom potential energy rather than cohesive energy as some potentials have non-zero isolated atom energies.
- 2019-02-04. Values regenerated with even r spacings of 0.02 Å, and now include values less than 2 Å when possible. Updated calculation method and parameters enhance compatibility with more potential styles.
- 2019-04-26. Results for hcp, double hcp, α-As and L10 prototypes regenerated from different unit cell representations. Only α-As results show noticable (>1e-5 eV) difference due to using a different coordinate for Wykoff site c position.
- 2018-06-13. Values for MEAM potentials corrected. Dynamic versions of the plots moved to separate pages to improve page loading. Cosmetic changes to how data is shown and updates to the documentation.
- 2017-01-11. Replaced png pictures with interactive Bokeh plots. Data regenerated with 200 values of r instead of 300.
- 2016-09-28. Plots for binary structures added. Data and plots for elemental structures regenerated. Data values match the values of the previous version. Data table formatting slightly changed to increase precision and ensure spaces between large values. Composition added to plot title and structure names made longer.
- 2016-04-07. Plots for elemental structures added.
