jp8b07823_si_001.pdf (150.03 kB)
Noncollinear Relativistic DFT + U Calculations of Actinide Dioxide Surfaces
journal contribution
posted on 2018-12-06, 00:00 authored by James T. Pegg, Ashley E. Shields, Mark T. Storr, David O. Scanlon, Nora H. de LeeuwA noncollinear
relativistic PBEsol + U study of
low-index actinide dioxides (AnO2, An = U, Np, or Pu) surfaces
has been conducted. The importance of magnetic vector reorientation
relative to the plane of the surface is highlighted; this has often
been ignored in collinear nonrelativistic models. The use of noncollinear
relativistic methods is key to the design of reliable computational
models. The ionic relaxation of each surface is shown to be confined
to the first three monolayers, and we have explored the configurations
of the terminal oxygen ions on the reconstructed (001) surface. The
reconstructed (001) surfaces are ordered as (001)αβ <
(001)α < (001)β in terms of energetics. Electrostatic
potential isosurface and scanning tunneling microscopy images have
also been calculated. By considering the energetics of the low-index
AnO2 surfaces, an octahedral Wulff crystal morphology has
been calculated.