Interatomic potential for accurate phonons and defects in UO2

Alexander E. Thompson, Bryce Meredig, Marius Stan, C. Wolverton*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

We have developed an improved uranium dioxide interatomic potential by fitting to forces, energies, and stresses of first principles molecular dynamics calculations via a genetic algorithm approach called Iterative Potential Refinement (IPR). We compare the defect energetics and vibrational properties of the IPR-fit potential with other interatomic potentials, density functional theory calculations, and experimental phonon dispersions. We find that among previously published potentials examined, there is no potential that simultaneously yields accurate defect energetics and accurate vibrational properties. In contrast, our IPR-fit potential produces both accurate defects and the best agreement with the experimental phonon dispersion and phonon density of states. This combination of accurate properties makes this IPR-fit potential useful for simulating UO2 in high temperature, defect-rich environments typical for nuclear fuel. Additionally, we verify that density functional theory with a Hubbard U correction accurately reproduces the experimentally derived UO2 phonon density of states.

Original languageEnglish (US)
Pages (from-to)155-162
Number of pages8
JournalJournal of Nuclear Materials
Volume446
Issue number1-3
DOIs
StatePublished - Mar 2014

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Materials Science(all)
  • Nuclear Energy and Engineering

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