Electronic structure of the strongly correlated electron system plutonium hexaboride: A study from single-particle approximations and many-body calculations.

The electronic structure of the strongly correlated electron system plutonium hexaboride is studied by using single-particle approximations and a many-body approach. Imaginary components of impurity Green's functions show that 5f and 5f manifolds are in conducting and insulating regimes, respectively. Quasi-particle weights and their ratio suggest that the intermediate coupling mechanism is applicable for Pu 5f electrons, and PuB might be in the orbital-selective localized state.

Electron correlation and relativistic effects on the electronic properties of a plutonium and americium mixed oxide (PuAmO): from single-particle approximation to dynamical mean-field theory.

First-principles calculations were performed on a plutonium and americium mixed oxide (PuAmO), aiming at revealing the effects of electron correlation, Pu/Am 5f-conduction electrons' hybridization, and relativity on its electronic properties. The many-body calculation suggests that the spin-orbit-coupling (SOC)-splitting of = 5/2 and = 7/2 manifolds are both in the weakly and moderately correlated states, respectively, implying that the coupling scheme is more appropriate for Pu/Am 5f electrons. The density of states, 5f occupation numbers, and Green's functions all suggest that both Pu and Am 5f electrons exhibit the coexistence of the localized and delocalized states.

Valence Fluctuation of Uranium Ions in Uranium Sesquinitride Revealed by Dynamical Mean-field Theory Merged with Density Functional Theory.

The electronic properties, in particular, the occupation number of 5f electrons and the valence state of U ions in uranium sesquinitride (U N ) are studied by using density functional theory (DFT) calculations merged with dynamical mean-field theory (DMFT). The results demonstrate that j=5/2 and j=7/2 manifolds are in the weakly correlated metallic and weakly correlated insulating regimes, respectively. The quasi-particle weights indicate that LS coupling scheme is more feasible for 5f electrons, which are not in the orbital-selective localized state.

Intermediate occupation numbers for 5f electrons in a Pu and U mixed oxide.

In order to reveal the correlation effect on the electronic properties in particular 5f electron occupation numbers of Pu/U ions in a (Pu,U) mixed oxide-PuUO4, a first principles calculation is performed by using density functional theory (DFT) plus a dynamical mean field theory (DMFT) scheme with the spin-orbit coupling (SOC) and on-site Coulomb repulsion for correlation effect due to localized Pu/U 5f orbitals. Results demonstrate that Pu/U 5f electron occupation numbers in the ground state of PuUO4 are mainly composed of 5f4/5f5 and 5f2/5f3 configurations, and exhibiting the intermediate occupation (IO) numbers with average 5f occupation numbers of about nf = 4.879 and 2.

The treatment of radioactive wastewater by ultrasonic standing wave method.

The radiation hazards of radionuclide arising from the storage of nuclear weapons cannot be ignored to the operators. Ultrasonic standing wave methods can be considered as the green cleaning separation techniques with high efficiency. The application of ultrasonic standing wave methods for liquid radioactive wastes treatment requires solving many problems connected with the proper selection of the frequency and power of ultrasonic transducers, and the processing time, etc.