TY  - THES
A1  - Remenyi, Christian
T1  - Density Functional Studies on EPR Parameters and Spin-Density Distributions of Transition Metal Complexes
T1  - Dichtefunktionalstudien zu EPR-Parametern und Spindichteverteilungen von Übergangsmetallkomplexen
N2  - In dieser Arbeit wurden EPR-Parameter und Spindichteverteilungen von Übergangsmetallkomplexen mit Hilfe der Dichtefunktionaltheorie (DFT) berechnet. Um das Potential der DFT bei der Beschreibung solcher Systeme zu zeigen, wurden mehrere Validierungsstudien durchgeführt, die in den Kapiteln 3-5 vorgestellt werden. Die Kapitel 6-8 beschäftigen sich dagegen eher mit konkreten chemischen Fragestellungen, die einige biologisch relevante Übergangsmetallkomplexe betreffen.
N2  - In this work we utilized Density Functional Theory to calculate EPR parameters and spin-density distributions of several transition metal complexes. To demonstrate the performance of our theoretical approach several validation studies were performed (Chapters 3-5). In contrast, the last three chapters of the thesis deal with specific chemical problems regarding several classes of biologically relevant transition metal complexes.
KW  - Dichtefunktionalformalismus
KW  - Elektronenspinresonanz
KW  - Spindichte
KW  - Übergangsmetall
KW  - DFT
KW  - EPR
KW  - Spindichte
KW  - g-Tensor
KW  - Hyperfeinkopplungstensor
KW  - DFT
KW  - EPR
KW  - Spin density
KW  - g-tensor
KW  - HFC-tensor
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-19848
ER  - 
TY  - JOUR
A1  - Engels, Bernd
T1  - Study of influences of various excitation classes on ab initio calculated isotropic hyperfine coupling constants
N2  - 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 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.
KW  - Organische Chemie
KW  - Spin density
KW  - Hyperfine coupling constants
KW  - Influence of excitation classes
KW  - Indirect and direct contributions to A<sub>iso</sub>
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58973
ER  -