Phonon and magnetic structure in δ-plutonium from density-functional theory

Journal Article · 29 October 2015 · Scientific Reports

DOI: https://doi.org/10.1038/srep15958 · OSTI ID:1262182

Söderlind, Per ^[1]; Zhou, F. ^[1]; Landa, A. ^[1]; Klepeis, J. E. ^[1]

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1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

We present phonon properties of plutonium metal obtained from a combination of density-functional-theory (DFT) electronic structure and the recently developed compressive sensing lattice dynamics (CSLD). The CSLD model is here trained on DFT total energies of several hundreds of quasi-random atomic configurations for best possible accuracy of the phonon properties. The calculated phonon dispersions compare better with experiment than earlier results obtained from dynamical mean-field theory. The density-functional model of the electronic structure consists of disordered magnetic moments with all relativistic effects and explicit orbital-orbital correlations. The magnetic disorder is approximated in two ways: (i) a special quasi-random structure and (ii) the disordered-local-moment (DLM) method within the coherent potential approximation. Magnetism in plutonium has been debated intensely, However, the present magnetic approach for plutonium is validated by the close agreement between the predicted magnetic form factor and that of recent neutron-scattering experiments.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC52-07NA27344
• OSTI ID: 1262182
• Report Number(s): LLNL-JRNL-676061
• Journal Information: Scientific Reports, Journal Name: Scientific Reports Vol. 5; ISSN 2045-2322
• Publisher: Nature Publishing GroupCopyright Statement
• Country of Publication: United States
• Language: English