TY - JOUR A1 - Staikova, M. A1 - Engels, Bernd A1 - Peric, M. A1 - Peyerimhoff, S. D. T1 - Ab initio calculation of the vibronically averaged hyperfine coupling constants in the two lowest electronic states of H\(_2\)O\(^+\) N2 - No abstract available T2 - Ab initio calculations of the vibronically averaged hyperfine coupling constants in the 1\(^2\)Π\(_u\)(X\(^2\)B\(_1\),A\(^2\)A\(_1\)) state of the water cation KW - Organische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58998 ER - TY - JOUR A1 - Gittins, C. M. A1 - Harris, N. A. A1 - Field, R. W. A1 - Verges, J. A1 - Ernst, W. E. A1 - Bündgen, P. A1 - Engels, Bernd T1 - Analysis and Depertubation of the C\(^2\)Π and D\(^2\)Σ\(^+\) states of CaF N2 - No abstract available KW - Organische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58980 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 Aiso Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58973 ER - TY - JOUR A1 - Metropoulos, B. A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - On the chemi-ionization reaction O + CH ----> HCO\(^+\)+ e\(^-\). Coollinear O-CH Approach N2 - We have investigated theoretically the importance of the O(\(^3\)P)+CH(a\(^4\sum^-\)) and the O(\(^3\)P)+CH(X\(^2\Pi\)) channels in the collinear chemi-ionization reaction O+CH->HCO\(^+\) +e\(^-\). We have found that both channels may lead to chemi-ionization via favorable Franck-Condon overlaps with the states ofthe ionic species. KW - Organische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58963 ER - TY - JOUR A1 - Bentley, T. W. A1 - Norman, S. J. A1 - Gerstner, E. A1 - Kemmer, R. A1 - Christl, Manfred T1 - Solvolysis of Tricyclo[3.1.0.0\(^{2,6}\)]hex-3-yl and Bicyclo[2.1.1]hex-2-yl Sulfonates N2 - No abstract available KW - Organische Chemie KW - Bicyclo[1.1.0]butylcarbinyl sulfonates KW - solvolysis of KW - Cyclobutylcarbinyl sulfonates KW - Anchimeric assistance in solvolysis KW - Rearrangement of carbocations KW - Electron demand in ditosylates Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58689 ER -