DFT + <i>U</i> Study of Uranium Dioxide and Plutonium Dioxide with Occupation Matrix Control

Chen, Jiali; Kaltsoyannis, Nikolas

doi:10.1021/acs.jpcc.2c03804

Cited by 22 publications

(18 citation statements)

References 54 publications

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“…The authors have cited additional references within the Supporting Information. [54][55][56][57][58][59][60][61][62][63][64][65] Appendix NU-1700 MOFid/MOFkey: [53] MOFkey: U.CVDALFASPVBUKU.MOFkey-v1.tbo MOFid:…”

Section: Supporting Informationmentioning

confidence: 99%

Evidence of a Uranium‐Paddlewheel Node in a Catecholate‐Based Metal–Organic Framework

et al. 2023

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The interactions between uranium and non‐innocent organic species are an essential component of fundamental uranium redox chemistry. However, they have seldom been explored in the context of multidimensional, porous materials. Uranium‐based metal–organic frameworks (MOFs) offer a new angle to study these interactions, as these self‐assembled species stabilize uranium species through immobilization by organic linkers within a crystalline framework, while potentially providing a method for adjusting metal oxidation state through coordination of non‐innocent linkers. We report the synthesis of the MOF NU‐1700, assembled from U4+‐paddlewheel nodes and catecholate‐based linkers. We propose this highly unusual structure, which contains two U4+ ions in a paddlewheel built from four linkers—a first among uranium materials—as a result of extensive characterization via powder X‐ray diffraction (PXRD), sorption, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA), in addition to density functional theory (DFT) calculations.

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Section: Supporting Informationmentioning

confidence: 99%

Evidence of a Uranium‐Paddlewheel Node in a Catecholate‐Based Metal–Organic Framework

et al. 2023

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“…They also lie in the range of values used in our previous simulations of these materials using the VASP code. 9 The same value of the Hubbard U is added to the An for both An L edge and O K edge XANES simulations (see below). Both experiment and previous simulation have found a noncollinear antiferromagnetic (AFM) ground state for UO 2 .…”

Section: ■ Computational Background and Detailsmentioning

confidence: 99%

DFT + U Simulation of the X-ray Absorption Near-Edge Structure of Bulk UO₂ and PuO₂

Chen,

Blaha,

Kaltsoyannis

2023

J. Phys. Chem. C

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Hubbard U-corrected density functional theory within the periodic boundary condition model in the WIEN2k code is used to simulate the actinide L III and O K edge Xray absorption near-edge structure (XANES) for UO 2 and PuO 2 . Spin-orbit coupling effects are included, as are possible excitonic effects using supercells with a core hole on one of the atoms. Our calculations yield spectra in excellent agreement with previous experiments and superior to previous simulations. Density of states analysis reveals the mechanism behind the XANES peaks: the main contribution to the U/Pu L III edges comes from the U/Pu d states hybridized with O p states, while as expected, the O p states primarily determine the O K edges of both UO 2 and PuO 2 . The O K edges also feature O p hybridizing with U/Pu d and f states in the low-energy region and with U/Pu s and p states for the higher-energy peaks.

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“…Atomistic approaches are also investigated using firstprinciples calculations based on density functional theory (DFT), often coupled to the Hubbard's model (DFT + U), or empirical potentials (EPs). Molecular dynamics (MD) simulations can subsequently be carried out for computing the diffusivity of some species in actinide dioxides (Freyss et al, 2005;Dorado et al, 2010;Boyarchenkov et al, 2013;Cooper et al, 2015;Matthews et al, 2019;Wang et al, 2019;Nekrasov et al, 2021;Chen and Kaltsoyannis, 2022;Cooper, 2022).…”

Section: Computational Approachmentioning

confidence: 99%

Cation interdiffusion in uranium–plutonium mixed oxide fuels: Where are we now?

Vauchy

Hirooka²,

Matsumoto³

et al. 2022

Front. Nucl. Eng.

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The diffusion phenomena in uranium–plutonium mixed oxides U1−yPuyO2 dictate the physicochemical properties of mixed oxides (MOX) nuclear fuel throughout manufacturing, irradiation, and storage. More precisely, it is paramount to estimate the cation interdiffusion insofar as it dovetails with the actinide redistribution during sintering and under irradiation. This paper draws a critical review of the existing experimental data of U and Pu interdiffusion coefficients in MOX fuel.

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DFT + U Study of Uranium Dioxide and Plutonium Dioxide with Occupation Matrix Control

Cited by 22 publications

References 54 publications

Evidence of a Uranium‐Paddlewheel Node in a Catecholate‐Based Metal–Organic Framework

Evidence of a Uranium‐Paddlewheel Node in a Catecholate‐Based Metal–Organic Framework

DFT + U Simulation of the X-ray Absorption Near-Edge Structure of Bulk UO₂ and PuO₂

Cation interdiffusion in uranium–plutonium mixed oxide fuels: Where are we now?

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DFT + U Study of Uranium Dioxide and Plutonium Dioxide with Occupation Matrix Control

Cited by 22 publications

References 54 publications

Evidence of a Uranium‐Paddlewheel Node in a Catecholate‐Based Metal–Organic Framework

Evidence of a Uranium‐Paddlewheel Node in a Catecholate‐Based Metal–Organic Framework

DFT + U Simulation of the X-ray Absorption Near-Edge Structure of Bulk UO2 and PuO2

Cation interdiffusion in uranium–plutonium mixed oxide fuels: Where are we now?

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DFT + U Simulation of the X-ray Absorption Near-Edge Structure of Bulk UO₂ and PuO₂