The actinide oxides, nitrides, and carbides are of both fundamental and applied interest. A number of basic properties associated with their electronic structure are still not known; this includes magnetic ordering, optical gaps, and resistivity and so on. In the work, we systemically investigate structural and electronic properties of actinide materials across from oxides to nitrides to carbides via performing Screened Hybrid Density Functional (HSE) approach which have met with some success in the Mott insulators.        Our computed results show that the hybrid HSE functional gives a better description of the electronic (magnetic states, density of states, band gap and optical properties, etc.) and structural properties (lattice constant, bond length, etc.) for actinide dioxides, strongly correlated insulator series when compared with available experimental data from our collaboration groups at LANL. However, there are still some problems on predicting the electronic properties of actinide nitrides and carbides which mainly fall in strongly correlated metals, indicating that screened hybrid DFT is missing key physics for the remaining piece of the puzzle, the correlated metallic regime. In addition, to compare with the results by HSE, the structures, electronic and magnetic properties of these actinide compounds are also investigated by performing PBE and PBE+U approximation. Roughly speaking, PBE gives a wrong prediction on the ground states of these materials and electronic properties of Mott insulators, however, it offers a good description on electronic properties for the correlated metallic systems. In a certain way, the prediction on electronic structure from PBE+U is similar to those by HSE, while the computed lattice constants by PBE+U are far away from these values. HSE values are in good agreement with the experimental data.

Screened hybrid density functional prediction for actinide materials

246th National Meeting (2013)

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