GGA+U study of uranium mononitride: A comparison of the U-ramping and occupation matrix schemes and incorporation energies of fission products

Uranium mononitride is studied in the DFT + U framework. Its ground state is investigated and a study of the incorporation of diverse fission products in the crystal is conducted. The U-ramping and occupation matrix control (OMC) schemes are used to eliminate metastable states. Beyond a certain amou...

Full description

Saved in:
Bibliographic Details
Published in:Journal of nuclear materials 2016-09, Vol.478, p.119-124
Main Authors: Claisse, Antoine, Klipfel, Marco, Lindbom, Niclas, Freyss, Michel, Olsson, Pär
Format: Article
Language:English
Subjects:
Condensed Matter
Materials Science
Physics
Strongly Correlated Electrons
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Uranium mononitride is studied in the DFT + U framework. Its ground state is investigated and a study of the incorporation of diverse fission products in the crystal is conducted. The U-ramping and occupation matrix control (OMC) schemes are used to eliminate metastable states. Beyond a certain amount of introduced correlation, the OMC scheme starts to find a lower total energy. The OMC scheme is chosen for the second part of this study. Furthermore, the influence of the magnetic ordering is studied using the U-ramping method, showing that antiferromagnetic order is the most stable one when the U parameter is larger than 1.75 eV. The effect on the density of states is investigated and elastic constants are provided for comparison with other methods and experiments. The incorporation energies of fission products in different defect configurations are calculated and these energies are corrected to take into account the limited size of the supercell. •We studied bulk uranium nitride with means of DFT+U with the U-ramping scheme and the OMC scheme.•We produces a density of states plot and calculated the elastic constants of UN.•We calculated the incorporation energy of many fission products in UN, and corrected them to take into account the elastic interactions.•The OMC scheme should be used over the U-ramping scheme.•Fission products go to larger crystal sites.
ISSN:0022-3115
1873-4820
DOI:10.1016/j.jnucmat.2016.06.007