Cation Vacancies with and without O-O Dimerization: Identifying Reconstructed Defect Configurations in Metal Oxides.
7 affiliations
- 1National & Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials, Henan University, Kaifeng475004, P. R. China.
- 2Kathleen Lonsdale Materials Chemistry, Department of Chemistry, University College London, 20 Gordon Street, LondonWC1H0AJ, United Kingdom.
- 3Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056Basel, Switzerland.
- 4Institute of Photonic Chips, University of Shanghai for Science and Technology, 580 Jungong Road, Shanghai200093, China.
- 5Scientific Computing Department, STFC Daresbury Laboratory, WarringtonWA4 4AD, Cheshire, United Kingdom.
- 6School of Engineering and Design, London South Bank University, 103 Borough Road, LondonSE1 OAA, United Kingdom.
- 7School of Chemistry, Cardiff University, Park Place, CardiffCF10 1AT, United Kingdom.
Abstract
Point defects in solid-state materials are conventionally modeled as lattice-derived defects, generated by adding or removing atoms from symmetric bulk lattice structures, followed by local geometry optimization. This approach often yields symmetric, weakly relaxed local minima that remain close to the parent lattice. Here, we show that this assumption can fail qualitatively for vacancies in many metal oxides. Rather than retaining a lattice-derived geometry with localized holes on oxygen sites, cation vacancies can drive extensive reconstruction, producing defect configurations in which the O-O bonds and O-O-O chains become the preferred charge-compensation motifs. We combined the minima hopping (MH) structure prediction algorithm with machine-learned interatomic potentials (MLIPs), hybrid QM/MM embedded-cluster calculations, and periodic density functional theory (DFT) calculations to investigate cation vacancies across a broad series of metal oxides. Our results show a clear oxidation-state-dependent trend. In the charge-neutral state, cation vacancies in oxides with formal oxidation states of +4 or higher favor reconstructed defect configurations containing O-O bonds or O-O-O chains with bond lengths of approximately 1.4 Å, lowering the defect formation energy by up to several electronvolts relative to the conventional structure. By contrast, in oxides with lower cation oxidation states, such reconstructions are generally unfavorable at charge neutrality but can become energetically more favorable at positive charge states. These findings define oxygen-bond formation as a general reconstruction pathway for cation vacancies in metal oxides and show that global structure searches are essential for predictive defect modeling beyond conventional lattice-derived local minima.
Related
- Highly twinned cobalt selenide with abundant selenium vacancies for efficient nitrogen reduction reaction
- Nonradiative energy transfer between boron vacancies in hexagonal boron nitride and other two-dimensional materials
- Excited state modulation of C70 dimerization in a carbon nanotube under a variable electron acceleration voltage
- Defect Chemistry and Electronic Structure of α-Pu2O3: A Hybrid DFT Study of Charged Vacancies, Interstitials, and Antisites
- Complete stabilization of surface oxygen vacancies in high-entropy oxides
BibTeX
@article{liu2026cation,
title = {{Cation Vacancies with and without O-O Dimerization: Identifying Reconstructed Defect Configurations in Metal Oxides.}},
author = {Taifeng Liu and Xingfan Zhang and Jamal Abdul Nasir and Qing Hou and Liam Morgan and Jingcheng Guan and Thomas Durrant and You Lu and Thomas W Keal and John Buckeridge and Scott M Woodley and Stefan Goedecker and C Richard A Catlow and Alexey A Sokol},
journal = {Journal of the American Chemical Society},
year = {2026},
month = oct,
doi = {10.1021/jacs.6c15378},
url = {https://europepmc.org/article/MED/42912303},
note = {CC BY},
}
RIS
TY - JOUR
TI - Cation Vacancies with and without O-O Dimerization: Identifying Reconstructed Defect Configurations in Metal Oxides.
AU - Taifeng Liu
AU - Xingfan Zhang
AU - Jamal Abdul Nasir
AU - Qing Hou
AU - Liam Morgan
AU - Jingcheng Guan
AU - Thomas Durrant
AU - You Lu
AU - Thomas W Keal
AU - John Buckeridge
AU - Scott M Woodley
AU - Stefan Goedecker
AU - C Richard A Catlow
AU - Alexey A Sokol
PY - 2026
DA - 2026/10/01
JO - Journal of the American Chemical Society
DO - 10.1021/jacs.6c15378
UR - https://europepmc.org/article/MED/42912303
AB - Point defects in solid-state materials are conventionally modeled as lattice-derived defects, generated by adding or removing atoms from symmetric bulk lattice structures, followed by local geometry optimization. This approach often yields symmetric, weakly relaxed local minima that remain close to the parent lattice. Here, we show that this assumption can fail qualitatively for vacancies in many metal oxides. Rather than retaining a lattice-derived geometry with localized holes on oxygen sites, cation vacancies can drive extensive reconstruction, producing defect configurations in which the O-O bonds and O-O-O chains become the preferred charge-compensation motifs. We combined the minima hopping (MH) structure prediction algorithm with machine-learned interatomic potentials (MLIPs), hybrid QM/MM embedded-cluster calculations, and periodic density functional theory (DFT) calculations to investigate cation vacancies across a broad series of metal oxides. Our results show a clear oxidation-state-dependent trend. In the charge-neutral state, cation vacancies in oxides with formal oxidation states of +4 or higher favor reconstructed defect configurations containing O-O bonds or O-O-O chains with bond lengths of approximately 1.4 Å, lowering the defect formation energy by up to several electronvolts relative to the conventional structure. By contrast, in oxides with lower cation oxidation states, such reconstructions are generally unfavorable at charge neutrality but can become energetically more favorable at positive charge states. These findings define oxygen-bond formation as a general reconstruction pathway for cation vacancies in metal oxides and show that global structure searches are essential for predictive defect modeling beyond conventional lattice-derived local minima.
SN - 0002-7863
SN - 1520-5126
ER -