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Title: Role of quantum ion dynamics in the melting of lithium

Authors:
; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1323570
Grant/Contract Number:
AC52-07NA27344
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 94; Journal Issue: 10; Related Information: CHORUS Timestamp: 2016-09-09 18:11:48; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Elatresh, S. F., Bonev, S. A., Gregoryanz, E., and Ashcroft, N. W.. Role of quantum ion dynamics in the melting of lithium. United States: N. p., 2016. Web. doi:10.1103/PhysRevB.94.104107.
Elatresh, S. F., Bonev, S. A., Gregoryanz, E., & Ashcroft, N. W.. Role of quantum ion dynamics in the melting of lithium. United States. doi:10.1103/PhysRevB.94.104107.
Elatresh, S. F., Bonev, S. A., Gregoryanz, E., and Ashcroft, N. W.. 2016. "Role of quantum ion dynamics in the melting of lithium". United States. doi:10.1103/PhysRevB.94.104107.
@article{osti_1323570,
title = {Role of quantum ion dynamics in the melting of lithium},
author = {Elatresh, S. F. and Bonev, S. A. and Gregoryanz, E. and Ashcroft, N. W.},
abstractNote = {},
doi = {10.1103/PhysRevB.94.104107},
journal = {Physical Review B},
number = 10,
volume = 94,
place = {United States},
year = 2016,
month = 9
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevB.94.104107

Citation Metrics:
Cited by: 1work
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  • The melting and lattice dynamics of sodium are studied by quantum molecular dynamics simulation, i.e., with allowance for anharmonicity, at pressures up to 1 Mbar and temperatures up to 1000 K. The simulation results agree well with the experimental data and our earlier calculation performed ab initio in the quasi-harmonic approximation. The simulation results demonstrate that anharmonic interactions weakly affect the melting curve and the phonon frequencies of Na up to near-melting temperatures.
  • The melting point of liquid lithium near zero pressure is studied with large-scale orbital-free first-principles molecular dynamics (OF-FPMD) in the isobaric-isothermal ensemble. Here, we adopt the Wang-Govind-Carter (WGC) functional as our kinetic energy density functional (KEDF) and construct a bulk-derived local pseudopotential (BLPS) for Li. Our simulations employ both the ‘heat-until-melts’ method and the coexistence method. We predict 465 K as an upper bound of the melting point of Li from the ‘heat-until-melts’ method, while we predict 434 K as the melting point of Li from the coexistence method. These values compare well with an experimental melting point of 453more » K at zero pressure. Furthermore, we calculate a few important properties of liquid Li including the diffusion coefficients, pair distribution functions, static structure factors, and compressibilities of Li at 470 K and 725 K in the canonical ensemble. This theoretically-obtained results show good agreement with known experimental results, suggesting that OF-FPMD using a non-local KEDF and a BLPS is capable of accurately describing liquid metals.« less
  • Using a self-developed combination of the thermodynamic integration and the ab initio path-integral molecular dynamics methods, we quantitatively studied the influence of nuclear quantum effects (NQEs) on the melting of dense lithium at 45 GPa. We find that although the NQEs significantly change the free-energies of the competing solid and liquid phases, the melting temperature (T{sub m}) is lowered by only ∼15 K, with values obtained using both classical and quantum nuclei in close proximity to a new experiment. Besides this, a substantial narrowing of the solid/liquid free-energy differences close to T{sub m} was observed, in alignment with a tendencymore » that glassy states might form upon rapid cooling. This tendency was demonstrated by the dynamics of crystallization in the two-phase simulations, which helps to reconcile an important conflict between two recent experiments. This study presents a simple picture for the phase diagram of lithium under pressure. It also indicates that claims on the influence of NQEs on phase diagrams should be carefully made and the method adopted offers a robust solution for such quantitative analyses.« less
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