Description of polarons in ceria using Density Functional Theory

4th Workshop on Theory, Modelling and Computational Methods for Semiconductors

物理学;计算机科学

Castleton, Christopher W.M.^1 ; Lee, Amy L.^1 ; Kullgren, Jolla^2 ; Hermansson, Kersti^2

School of Science and Technology, Nottingham Trent University, NG11 8NS, United Kingdom^1

Department of Chemistry, Uppsala University, Box 538, Uppsala, Sweden^2

关键词: EmptyState;    Functionals;    GGA + U;    LDA + U;    Various densities;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/526/1/012002/pdf
DOI  :  10.1088/1742-6596/526/1/012002

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

The performance of various density functional theory (DFT) functionals in reproducing the localization of Ce4f electrons to form polarons in cerium dioxide (ceria) is studied. It is found that LDA+U with U=6 eV provides the best description, followed by GGA+U with U=5 eV. Hybrids perform worse, with PBE0 better than HSE06 and HSE03. It is also demonstrated that the improvement in the description of the polarons obtained from LDA+U and GGA+U is due primarily to the effect the U has on the filled Ce4f states, but the improvement obtained using the hybrids is primarily due to their effect on the empty states. This difference can be expected to strongly impact some detailed predictions for the properties of ceria obtained using the two classes of functional.