First-Principles Calculation of Point Defects in Uranium Dioxide

Iwasawa, Misako; Chen, Ying; Kaneta, Yasunori; Ohnuma, Toshiharu; Geng, Hua-Yun; Kinoshita, Motoyasu

doi:10.2320/matertrans.47.2651

Cited by 105 publications

(96 citation statements)

References 24 publications

(24 reference statements)

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“…A somewhat better agreement is observed within the generalized gradient approximation 26 , i.e. GGA+U 10,[27][28][29] . Note that following Dudarev's calculations, we 55 employed recently the same values of U and J in our study on bulk properties and defects behaviour in UO 2 10 .…”

Section: Computational Detailsmentioning

confidence: 87%

Density functional theory calculations on magnetic properties of actinide compounds

Gryaznov

Heifets

Sedmidubský

2010

Phys. Chem. Chem. Phys.

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We have performed a detailed analysis of the magnetic (collinear and noncollinear) order and atomic and the electron structures of UO 2 , PuO 2 and UN on the basis of density functional theory with the Hubbard electron correlation correction (DFT+U). We have shown that the 3-k magnetic structure of UO 2 is the lowest in energy for the Hubbard parameter value of U=4.6 eV (and J=0.5 10 eV) consistent with experiments when Dudarev's formalism is used. In contrast to UO 2 , UN and PuO 2 show no trend for a distortion towards rhombohedral structure and, thus, no complex 3-k magnetic structure is to be anticipated in these materials.

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Section: Computational Detailsmentioning

confidence: 87%

Density functional theory calculations on magnetic properties of actinide compounds

Gryaznov

Heifets

Sedmidubský

2010

Phys. Chem. Chem. Phys.

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“…For a neutral oxygen interstitial defect, calculated formation energies range from À0.44 to À2.17 eV with no apparent cause for the differences in the methodologies employed. [20][21][22][23][24] To investigate this problem, Dorado et al considered the occupation of f orbitals in bulk UO 2 using both the Liechtenstein and Dudarev DFT + U approaches. 16,17 To further examine this effect, they implemented a methodology to allow them to control which f orbitals were occupied, allowing a search of different orbital occupations.…”

Section: Introductionmentioning

confidence: 99%

Occupation matrix control of d- and f-electron localisations using DFT + U

Allen

Watson

2014

Phys. Chem. Chem. Phys.

201

200

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The use of a density functional theory methodology with on-site corrections (DFT + U) has been repeatedly shown to give an improved description of localised d and f states over those predicted with a standard DFT approach. However, the localisation of electrons also carries with it the problem of metastability, due to the possible occupation of different orbitals and different locations. This study details the use of an occupation matrix control methodology for simulating localised d and f states with a plane-wave DFT + U approach which allows the user to control both the site and orbital localisation.This approach is tested for orbital occupation using octahedral and tetrahedral Ti(III) and Ce(III) carbonyl clusters and for orbital and site location using the periodic systems anatase-TiO 2 and CeO 2 . The periodic cells are tested by the addition of an electron and through the formation of a neutral oxygen vacancy (leaving two electrons to localise). These test systems allow the successful study of orbital degeneracies, the presence of metastable states and the importance of controlling the site of localisation within the cell, and it highlights the use an occupation matrix control methodology can have in electronic structure calculations.

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“…According to reference II, the U vacancy could be substantially easier formed at T = 0 K than the N vacancy. Notice that the chemical potentials of O and U atoms used in similar defect studies in UO 2 bulk did not reveal the energetic preference for the U-vacancy [50,53]. The defectdefect interaction is not responsible for this effect as Table 3).…”

Section: Number Of Layersmentioning

confidence: 88%