Lattice dynamics and elasticity for εplutonium [Firstprinciples lattice dynamics for εplutonium]
Abstract
Here, lattice dynamics and elasticity for the hightemperature ε phase (bodycentered cubic; bcc) of plutonium is predicted utilizing firstprinciples electronic structure coupled with a selfconsistent phonon method that takes phononphonon interaction and strong anharmonicity into account. These predictions establish the first sensible latticedynamics and elasticity data on εPu. The atomic forces required for the phonon scheme are highly accurate and derived from the total energies obtained from relativistic and parameterfree densityfunctional theory. The results appear reasonable but no data exist to compare with except those from dynamical meanfield theory that suggest εplutonium is mechanically unstable. Fundamental knowledge and understanding of the hightemperature bcc phase, that is generally present in all actinide metals before melting, is critically important for a proper interpretation of the phase diagram as well as practical modeling of hightemperature properties.
 Authors:
 Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
 Publication Date:
 Research Org.:
 Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
 Sponsoring Org.:
 USDOE
 OSTI Identifier:
 1357362
 Alternate Identifier(s):
 OSTI ID: 1366934
 Report Number(s):
 LLNLJRNL695423; LLNLJRNL695057
Journal ID: ISSN 20452322
 Grant/Contract Number:
 AC5207NA27344
 Resource Type:
 Journal Article: Accepted Manuscript
 Journal Name:
 Scientific Reports
 Additional Journal Information:
 Journal Volume: 7; Journal Issue: 1; Journal ID: ISSN 20452322
 Publisher:
 Nature Publishing Group
 Country of Publication:
 United States
 Language:
 English
 Subject:
 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; electronic properties and materials; phase transitions and critical phenomena
Citation Formats
Söderlind, Per. Lattice dynamics and elasticity for εplutonium [Firstprinciples lattice dynamics for εplutonium]. United States: N. p., 2017.
Web. doi:10.1038/s41598017010346.
Söderlind, Per. Lattice dynamics and elasticity for εplutonium [Firstprinciples lattice dynamics for εplutonium]. United States. doi:10.1038/s41598017010346.
Söderlind, Per. Tue .
"Lattice dynamics and elasticity for εplutonium [Firstprinciples lattice dynamics for εplutonium]". United States.
doi:10.1038/s41598017010346. https://www.osti.gov/servlets/purl/1357362.
@article{osti_1357362,
title = {Lattice dynamics and elasticity for εplutonium [Firstprinciples lattice dynamics for εplutonium]},
author = {Söderlind, Per},
abstractNote = {Here, lattice dynamics and elasticity for the hightemperature ε phase (bodycentered cubic; bcc) of plutonium is predicted utilizing firstprinciples electronic structure coupled with a selfconsistent phonon method that takes phononphonon interaction and strong anharmonicity into account. These predictions establish the first sensible latticedynamics and elasticity data on εPu. The atomic forces required for the phonon scheme are highly accurate and derived from the total energies obtained from relativistic and parameterfree densityfunctional theory. The results appear reasonable but no data exist to compare with except those from dynamical meanfield theory that suggest εplutonium is mechanically unstable. Fundamental knowledge and understanding of the hightemperature bcc phase, that is generally present in all actinide metals before melting, is critically important for a proper interpretation of the phase diagram as well as practical modeling of hightemperature properties.},
doi = {10.1038/s41598017010346},
journal = {Scientific Reports},
number = 1,
volume = 7,
place = {United States},
year = {Tue Apr 25 00:00:00 EDT 2017},
month = {Tue Apr 25 00:00:00 EDT 2017}
}

Lattice dynamics and elasticity for the hightemperature ε phase (bodycentered cubic; bcc) of plutonium is predicted utilizing firstprinciples electronic structure coupled with a selfconsistent phonon method that takes phononphonon interaction and strong anharmonicity into account. Our predictions establish the first sensible latticedynamics and elasticity data on εPu. The atomic forces required for the phonon scheme are highly accurate and derived from the total energies obtained from relativistic and parameterfree densityfunctional theory. These results appear reasonable but no data exist to compare with except those from dynamical meanfield theory that suggest εplutonium is mechanically unstable. Our fundamental knowledge and understanding ofmore »

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Inelastic neutron scattering measurements on silver oxide (Ag2O) with the cuprite structure were performed at temperatures from 40 to 400 K, and Fourier transform farinfrared spectra were measured from 100 to 300 K. The measured phonon densities of states and the infrared spectra showed unusually large energy shifts with temperature, and large linewidth broadenings. First principles molecular dynamics (MD) calculations were performed at various temperatures, successfully accounting for the negative thermal expansion (NTE) and local dynamics. Using the Fouriertransformed velocity autocorrelation method, the MD calculations reproduced the large anharmonic effects of Ag2O, and were in excellent agreement with the neutronmore »