We investigated the native point defects in CeO2 by the density functional (DFT) +U method,
and using a non-linear core-corrected norm-conserving Ce pseudopotential. We find the neutral
oxygen vacancy (VO
0) in CeO2 to have a very low formation energy of only 0.39eV in the Opoor
limit. It is a deep donor with negative U behavior, only stable in its neutral and doubly
positive states. The anion Frenkel defect is found to be the lowest energy disorder defect, with a
formation energy of only 2.08eV per defect site. These low formation energies arise from the
improved transferability of our Ce pseudopotential for its +3 and +4 valence states. The negative
U behavior of VO leads to excellent photo-catalytic behavior, while the low formation energy of
the anion Frenkel defect leads to a superior oxygen storage-and-release capability.All computing facilities and calculation resources receive funding from the Research Grant
Council, University Grants Committee of the HKSAR government. BH would like to thank the
fund support and calculations resources all supplied by the Department of Physics and Materials
Science, City University of Hong Kong.This is the accepted manuscript. The final version is available from ACS at http://pubs.acs.org/doi/abs/10.1021/jp506625h, under the title 'Study of CeO2 and Its Native Defects by Density Functional Theory with Repulsive Potential'