Study of influences of various excitation classes on ab initio calculated isotropic hyperfine coupling constants
Please always quote using this URN: urn:nbn:de:bvb:20-opus-58973
- Reliable prediction of the isotropic hyperfine coupling constant A\(_{iso}\) is still a difficult task for ab initio calculations. Strang dependence on the method employed for its ca1culation has been found. Within a CI ansatz A\(_{iso}\) is considerably affected by the excitation classes taken into account within the CI calculation. In the present work the influence of various excitation classes on A\(_{iso}\) is examined. Calculations including all single, double, triple and a large part of the quadruple excitations are performed and theReliable prediction of the isotropic hyperfine coupling constant A\(_{iso}\) is still a difficult task for ab initio calculations. Strang dependence on the method employed for its ca1culation has been found. Within a CI ansatz A\(_{iso}\) is considerably affected by the excitation classes taken into account within the CI calculation. In the present work the influence of various excitation classes on A\(_{iso}\) is examined. Calculations including all single, double, triple and a large part of the quadruple excitations are performed and the individual effects of the excitation classes are studied. It is found that the surprisingly good agreement found for S-CI treatments is due to large error cancellations. The importance of higher than double excitations arises from their indirect influence on the single excitations.…
Author: | Bernd Engels |
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URN: | urn:nbn:de:bvb:20-opus-58973 |
Document Type: | Journal article |
Faculties: | Fakultät für Chemie und Pharmazie / Institut für Organische Chemie |
Language: | English |
Year of Completion: | 1993 |
Source: | In: Theoretica Chimica Acta (1993) 86, 429-437. |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
GND Keyword: | Organische Chemie |
Tag: | Hyperfine coupling constants; Indirect and direct contributions to A<sub>iso</sub>; Influence of excitation classes; Spin density |
Release Date: | 2011/10/24 |
Licence (German): | Deutsches Urheberrecht |