Density functional theory calculations on magnetic properties of actinide compounds

Actinide compounds attract a great interest for both materials scientists and nuclear engineers being 5f-element based compounds used as nuclear fuels. Their properties, particularly relevant for uranium and plutonium compounds, combine strong electron correlation and relativistic effects. Only the combination of these two effects gives a proper description of magnetic structures in actinide compounds. Therefore, we have performed a detailed analysis of the magnetic structures and properties of UO2, PuO2 and UN on the basis of density functional theory with Hubbard electron correlation correction (DFT+U) as well as using hybrid functionals. Two plane wave DFT computer codes were employed, namely the pseudopotential code VASP [1] and the all-electron code Wien-2k [2]. The so-called DFT+U method incorporated in VASP [3] and the hybrid functionals in Wien-2k [4] are critically compared, in order to discuss the role of electron correlations and spin-orbit coupling effects. In particular, we compare the 1-k and 3-k magnetic structures for oxide compounds and underline how the strong correlations affect the magnetic behavior of UN predicted from DFT computations. In the frame of this analysis, we have applied different lattice distortions for all the three compounds and identified those giving the correct (experimental) description of the magnetic structures. All results obtained are discussed in the light of available experimental data and previous computations.

GRYAZNOV Denis;  SEDMIDUBSKY David;  HEIFETS E.; 

2010-12-15

ROYAL SOC CHEMISTRY

JRC56039

1463-9076,   

http://www1.cfi.lu.lv/teor/publications/2010/2010_17.pdf,    https://publications.jrc.ec.europa.eu/repository/handle/JRC56039,   

10.1039/C0CP00372G,