相关论文: First-principles study on oxidation effects in ura…
A comprehensive investigation on point defects and their clustering behavior in nonstoichiometric uranium dioxide UO2+x is carried out using LSDA+U method based on density functional theory. Accurate energetic information and charge…
We present a study of the structural phase transition, mechanical and thermodynamic properties of UO$_{2}$ by means of the local density approximation (LDA)$+U$ approach. A phase transition pressure of 40 GPa, which agrees well with the…
Plutonium dioxide is of high technological importance in nuclear fuel cycle and is particularly crucial in long-term storage of Pu-based radioactive waste. Using first-principles density-functional theory, in this paper we systematically…
Uranium dioxide (UO$_2$) remains a formidable challenge for first-principles approaches, due to the complex interplay among spin-orbit coupling, Mott physics, magnetic ordering, and crystal distortions. Here we use DFT+$U$ to explore UO$_2$…
A uniform distribution of point defects in an otherwise perfect crystallographic structure usually describes a unique pseudo phase of that state of a non-stoichiometric material. With off-stoichiometric uranium dioxide as a prototype, we…
The stability mechanism of cuboctahedral clusters in nonstoichiometric uranium dioxide is investigated by first-principles LSDA+U method. Calculations reveal that the structural stability is inherited from U6O12 molecular cluster whereas…
Making use of the energetics and equations of state of defective uranium dioxide that calculated with first-principles method, we demonstrate a possibility of constraining the formation energy of point defects by measuring the transition…
Self-defect clusters in bulk matrix might affect the thermodynamic behavior of fission gases in nuclear fuel such as uranium dioxide. With first-principles LSDA+U calculations and taking xenon as a prototype, we find that the influence of…
To explore the formation of noncollinear magnetic configurations in materials with strongly correlated electrons, we derive a noncollinear LSDA+$U$ model involving only one parameter $U$, as opposed to the difference between the Hubbard and…
The structural behavior of UO2 under high pressure up to 300GPa has been studied by first-principles calculations with LSDA+U approximation. The results show that a pressure-induced structural transition to the cotunnite-type (orthorhombic…
At the atomic scale, uranium-plutonium mixed oxides (U,Pu)O_2 are characterized by cationic chemical disorder, which entails that U and Pu cations are randomly distributed on the cation sublattice. In the present work, we study the impact…
Uranium is considered as a very important nuclear energy material because of the huge amount of energy released. As the main products of spontaneous decay of uranium, helium is difficult to react with uranium for its chemical inertness.…
By first-principles LSDA+U calculations, we revealed that the current physical picture of defective uranium dioxide suggested solely by neutron diffraction analysis is unsatisfactory. An understanding based on quantum theory has been…
The formalism of electronic density-functional-theory, with Hubbard-U corrections (DFT+U), is employed in a computational study of the energetics of U_{1-x} Ce_x O_2 mixtures. The computational approach makes use of a procedure which…
The structures, point defects and impacts of fission products for U3Si (\b{eta}-U3Si and {\gamma}-U3Si) and USi2 ({\alpha}-USi2 and \b{eta}-USi2) are studied by first-principles calculations. The lattice parameters of U3Si and USi2 are…
La1-xCaxMnO3+delta and La1-xNaxMnO3+delta samples with well defined cation molecularity and oxygen contents are analyzed with XRPD, electrical conductivity, electron paramagnetic resonance and static magnetization measurements. Point…
We perform first-principles calculations of the quasiparticle defect states, charge transition levels, and formation energies of oxygen vacancies in rutile titanium dioxide. The calculations are done within the recently developed combined…
The incorporation of oxygen atoms has been simulated into either nitrogen or uranium vacancy at the UN(001) surface, sub-surface or central layers. For calculations on the corresponding slab models both the relativistic pseudopotentials and…
We study the electronic structure of cubic phase uranium dioxide at different volumes using a combination of density functional theory and dynamical mean-field theory. The \emph{ab initio} calculations predict an orbital-selective Mott…
High pressure and high temperature properties of AB (A = $^6$Li, $^7$Li; B = H, D, T) are investigated with first-principles method comprehensively. It is found that the H$^{-}$ sublattice features in the low-pressure electronic structure…