Orthogonal tight binding model for silicon carbide
A new orthogonal tight binding (OTB) model for the silicon carbide (Si-C) system is presented. The model is parameterized in the reduced TB form which provides a critical step towards the development of an analytic bond-order potential (BOP) for Si-C. Coarse-grained from density functional theory (D...
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| Format: | Disertacija |
| Jezik: | English |
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2011
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| _version_ | 1826277447679606784 |
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| author | Kamenski, P |
| author2 | Pettifor, D |
| author_facet | Pettifor, D Kamenski, P |
| author_sort | Kamenski, P |
| collection | OXFORD |
| description | A new orthogonal tight binding (OTB) model for the silicon carbide (Si-C) system is presented. The model is parameterized in the reduced TB form which provides a critical step towards the development of an analytic bond-order potential (BOP) for Si-C. Coarse-grained from density functional theory (DFT), through TB, analytic BOPs address a number of the deficiencies of current interatomic potentials for Si-C including the neglect of explicit π-bonding and more accurate σ-bond contributions. Furthermore, the new reduced OTB model is important within TB in its own right as the first simple, selfconsistent OTB model parameterized specifically for SiC without the use of any averaging of elemental interactions. Selfconsistency is achieved through local charge neutrality (LCN). The distance-dependent functions used to define the Hamiltonian matrix elements in the two-centre approximation were obtained directly from given DFT-projected data, and repulsive parameters were fit to DFT binding energies. The electronic structure, binding energies, and heat of formation for the groundstate structures are reproduced well with no spurious groundstate structures found in a database of over 200 unique crystal structures. The significant improvements over existing OTB models for elemental Si and C and the binary SiC results show good promise for further applicability in modelling a wide range of phenomena in Si-C such as thin film growth or interfaces in general. |
| first_indexed | 2024-03-06T23:29:02Z |
| format | Thesis |
| id | oxford-uuid:6b63896b-770d-4fde-8be4-dbf2d063afa6 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T23:29:02Z |
| publishDate | 2011 |
| record_format | dspace |
| spelling | oxford-uuid:6b63896b-770d-4fde-8be4-dbf2d063afa62022-03-26T19:03:38ZOrthogonal tight binding model for silicon carbideThesishttp://purl.org/coar/resource_type/c_bdccuuid:6b63896b-770d-4fde-8be4-dbf2d063afa6Computer aided molecular and material designAtomic scale structure and propertiesMaterials SciencesPhysicsComputational chemistrySiliconSolid state chemistryCondensed Matter PhysicsCeramicsPhysical SciencesMaterials modellingAdvanced materialsChemistry & allied sciencesEnglishOxford University Research Archive - Valet2011Kamenski, PPettifor, DDrautz, RKolmogorov, AA new orthogonal tight binding (OTB) model for the silicon carbide (Si-C) system is presented. The model is parameterized in the reduced TB form which provides a critical step towards the development of an analytic bond-order potential (BOP) for Si-C. Coarse-grained from density functional theory (DFT), through TB, analytic BOPs address a number of the deficiencies of current interatomic potentials for Si-C including the neglect of explicit π-bonding and more accurate σ-bond contributions. Furthermore, the new reduced OTB model is important within TB in its own right as the first simple, selfconsistent OTB model parameterized specifically for SiC without the use of any averaging of elemental interactions. Selfconsistency is achieved through local charge neutrality (LCN). The distance-dependent functions used to define the Hamiltonian matrix elements in the two-centre approximation were obtained directly from given DFT-projected data, and repulsive parameters were fit to DFT binding energies. The electronic structure, binding energies, and heat of formation for the groundstate structures are reproduced well with no spurious groundstate structures found in a database of over 200 unique crystal structures. The significant improvements over existing OTB models for elemental Si and C and the binary SiC results show good promise for further applicability in modelling a wide range of phenomena in Si-C such as thin film growth or interfaces in general. |
| spellingShingle | Computer aided molecular and material design Atomic scale structure and properties Materials Sciences Physics Computational chemistry Silicon Solid state chemistry Condensed Matter Physics Ceramics Physical Sciences Materials modelling Advanced materials Chemistry & allied sciences Kamenski, P Orthogonal tight binding model for silicon carbide |
| title | Orthogonal tight binding model for silicon carbide |
| title_full | Orthogonal tight binding model for silicon carbide |
| title_fullStr | Orthogonal tight binding model for silicon carbide |
| title_full_unstemmed | Orthogonal tight binding model for silicon carbide |
| title_short | Orthogonal tight binding model for silicon carbide |
| title_sort | orthogonal tight binding model for silicon carbide |
| topic | Computer aided molecular and material design Atomic scale structure and properties Materials Sciences Physics Computational chemistry Silicon Solid state chemistry Condensed Matter Physics Ceramics Physical Sciences Materials modelling Advanced materials Chemistry & allied sciences |
| work_keys_str_mv | AT kamenskip orthogonaltightbindingmodelforsiliconcarbide |