- Title
- Reaction pathways in the solid state and the Hubbard U correction
- Creator
- Brown, Joshua J.; Page, Alister J.
- Relation
- ARC.LE170100032 http://purl.org/au-research/grants/arc/FL170100032
- Relation
- Journal of Chemical Physics Vol. 154, Issue 12, no. 124121
- Publisher Link
- http://dx.doi.org/10.1063/5.0045526
- Publisher
- AIP
- Resource Type
- journal article
- Date
- 2021
- Description
- We investigate how the Hubbard U correction influences vacancy defect migration barriers in transition metal oxide semiconductors. We show that, depending on the occupation of the transition metal d orbitals, the Hubbard U correction can cause severe instabilities in the migration barrier energies predicted using generalized gradient approximation density functional theory (GGA DFT). For the d0 oxide SrTiO3, applying a Hubbard correction to the Ti4+ 3d orbitals below 4–5 eV yields a migration barrier of ∼0.4 eV. However, above this threshold, the barrier increases suddenly to ∼2 eV. This sudden increase in the transition state barrier arises from the Hubbard U correction changing the Ti4+ t2g/eg orbital occupation, and hence electron density localization, along the migration pathway. Similar results are observed in the d10 oxide ZnO; however, significantly larger Hubbard U corrections must be applied to the Zn2+ 3d orbitals for the same instability to be observed. These results highlight important limitations to the application of the Hubbard U correction when modeling reactive pathways in solid state materials using GGA DFT.
- Subject
- Hubbard U correction; pathway; transition state; solid state materials
- Identifier
- http://hdl.handle.net/1959.13/1474742
- Identifier
- uon:49353
- Identifier
- ISSN:0021-9606
- Rights
- This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Brown, Joshua J.; Page, Alister J. ‘Reaction pathways in the solid state and the Hubbard U correction’. Published in Journal of Chemical Physics Vol. 154, Issue 12, no. 124121 (2021) and may be found at http://dx.doi.org/10.1063/5.0045526.
- Language
- eng
- Full Text
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