Quantum mechanical vs. empirical potential modeling of uranium dioxide (UO2) surfaces: (111), (110), and (100)
To evaluate the stability, potential reactivity, and relaxation mechanisms on different uraninite surfaces, surface energy values were calculated and structural relaxation was determined for the (111), (110), and (100) crystallographic faces of uranium dioxide (UO2) using quantum mechanical (density...
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| Format: | Journal Article |
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Mineralogical Society of America
2006
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| Online Access: | http://hdl.handle.net/20.500.11937/7415 |
| _version_ | 1848745361573675008 |
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| author | Skomurski, F. Ewing, R. Rohl, Andrew Gale, Julian Becker, U. |
| author_facet | Skomurski, F. Ewing, R. Rohl, Andrew Gale, Julian Becker, U. |
| author_sort | Skomurski, F. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | To evaluate the stability, potential reactivity, and relaxation mechanisms on different uraninite surfaces, surface energy values were calculated and structural relaxation was determined for the (111), (110), and (100) crystallographic faces of uranium dioxide (UO2) using quantum mechanical (density functional theory) and empirical potential computational methods. Quantum mechanical results are compared with empirical potential results, which use surface slab models with two different geometries, as well as various different empirical force fields. The strengths and weaknesses of the different approaches are evaluated, and surface stabilizing mechanisms such as relaxation, charge redistribution, and electronic stabilization are investigated. Quantum mechanical (q.m.) surface energy results are in agreement with the relative surface energy trends resulting from calculations using three different empirical potential sets for uranium and oxygen (two from Catlow 1977; one from Meis and Gale 1998), and with empirical force-field values published in the literature (Abramowski et al. 1999, 2001). The (111) surface consistently has the lowest surface energy (0.461 J/m2 from q.m. calculations) and the smallest amount of surface relaxation, followed by the (110) surface (0.846 J/m2; q.m.), and the (100) surface (1.194 J/m2; q.m.) (quantum mechanical surface energy values in parentheses are for surface slabs with a thickness of four UO2 units). Differences exist, however, in the absolute values of surface energies calculated as a function of potential set used. Quantum mechanical values are consistently lower than values calculated using empirical potential methods. A fourth potential set is presented that is derived from fitting electrostatic and short-range repulsive parameters to experimental bulk properties and surface energies and relaxations from quantum mechanical calculations. |
| first_indexed | 2025-11-14T06:16:08Z |
| format | Journal Article |
| id | curtin-20.500.11937-7415 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:16:08Z |
| publishDate | 2006 |
| publisher | Mineralogical Society of America |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-74152017-10-02T02:28:16Z Quantum mechanical vs. empirical potential modeling of uranium dioxide (UO2) surfaces: (111), (110), and (100) Skomurski, F. Ewing, R. Rohl, Andrew Gale, Julian Becker, U. UO2 Uraninite quantum mechanical empirical potentials surface energy - uranium dioxide force ? elds To evaluate the stability, potential reactivity, and relaxation mechanisms on different uraninite surfaces, surface energy values were calculated and structural relaxation was determined for the (111), (110), and (100) crystallographic faces of uranium dioxide (UO2) using quantum mechanical (density functional theory) and empirical potential computational methods. Quantum mechanical results are compared with empirical potential results, which use surface slab models with two different geometries, as well as various different empirical force fields. The strengths and weaknesses of the different approaches are evaluated, and surface stabilizing mechanisms such as relaxation, charge redistribution, and electronic stabilization are investigated. Quantum mechanical (q.m.) surface energy results are in agreement with the relative surface energy trends resulting from calculations using three different empirical potential sets for uranium and oxygen (two from Catlow 1977; one from Meis and Gale 1998), and with empirical force-field values published in the literature (Abramowski et al. 1999, 2001). The (111) surface consistently has the lowest surface energy (0.461 J/m2 from q.m. calculations) and the smallest amount of surface relaxation, followed by the (110) surface (0.846 J/m2; q.m.), and the (100) surface (1.194 J/m2; q.m.) (quantum mechanical surface energy values in parentheses are for surface slabs with a thickness of four UO2 units). Differences exist, however, in the absolute values of surface energies calculated as a function of potential set used. Quantum mechanical values are consistently lower than values calculated using empirical potential methods. A fourth potential set is presented that is derived from fitting electrostatic and short-range repulsive parameters to experimental bulk properties and surface energies and relaxations from quantum mechanical calculations. 2006 Journal Article http://hdl.handle.net/20.500.11937/7415 10.2138/am.2006.2180 Mineralogical Society of America restricted |
| spellingShingle | UO2 Uraninite quantum mechanical empirical potentials surface energy - uranium dioxide force ? elds Skomurski, F. Ewing, R. Rohl, Andrew Gale, Julian Becker, U. Quantum mechanical vs. empirical potential modeling of uranium dioxide (UO2) surfaces: (111), (110), and (100) |
| title | Quantum mechanical vs. empirical potential modeling of uranium dioxide (UO2) surfaces: (111), (110), and (100) |
| title_full | Quantum mechanical vs. empirical potential modeling of uranium dioxide (UO2) surfaces: (111), (110), and (100) |
| title_fullStr | Quantum mechanical vs. empirical potential modeling of uranium dioxide (UO2) surfaces: (111), (110), and (100) |
| title_full_unstemmed | Quantum mechanical vs. empirical potential modeling of uranium dioxide (UO2) surfaces: (111), (110), and (100) |
| title_short | Quantum mechanical vs. empirical potential modeling of uranium dioxide (UO2) surfaces: (111), (110), and (100) |
| title_sort | quantum mechanical vs. empirical potential modeling of uranium dioxide (uo2) surfaces: (111), (110), and (100) |
| topic | UO2 Uraninite quantum mechanical empirical potentials surface energy - uranium dioxide force ? elds |
| url | http://hdl.handle.net/20.500.11937/7415 |