@article{PericEngels1992, author = {Peric, M. and Engels, Bernd}, title = {Ab initio calculation of the vibronically averaged hyperfine coupling constants in the 1\(^2\)Π\(_u\) electronic state of CH\(_2 ^+\)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58951}, year = {1992}, abstract = {The results of pure ab initio calculations of the hyperfine coupling constants for the 1 \(^2 \pi _u\) electronic state for various isotopomers of CHi in the energy range between 0 and 20 000 cm\(^{-1}\) are presented. Effects of vibronic and spin-orbit coupling are discussed.}, subject = {Organische Chemie}, language = {en} } @article{StaikovaEngelsPericetal.1993, author = {Staikova, M. and Engels, Bernd and Peric, M. and Peyerimhoff, S. D.}, title = {Ab initio calculation of the vibronically averaged hyperfine coupling constants in the two lowest electronic states of H\(_2\)O\(^+\)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58998}, year = {1993}, abstract = {No abstract available}, subject = {Organische Chemie}, language = {en} } @article{PericEngels1992, author = {Peric, M. and Engels, Bernd}, title = {Ab initio calculations of the vibronically averaged values for the hyperfine coupling constants in NH\(_2\), NHD and ND\(_2\)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58941}, year = {1992}, abstract = {Vibronically averaged values for K =0 and K = 1 bending levels in the energy range between 0 and 25 000 cm\(^{-1}\) are computed for the \(^{14}\)N, H, and D atoms in NH\(_2\), NHD, and ND\(_2\) The pure ab initio electronic potentials, as well as those derived by fitting of experimentally observed band positions are employed. Effects of vibronic coupling and local perturbations of close-lying levels belanging to different electronic states are discussed.}, subject = {Organische Chemie}, language = {en} } @article{StaikovaEngelsPeric1994, author = {Staikova, M. and Engels, Bernd and Peric, M.}, title = {Ab initio investigation of the hyperfine structure in the 1\(^2\)Π\(_u\)(X\(^2\)A\(_1\), A\(^2\)B\(_1\) system of BH\(_2\))}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59000}, year = {1994}, abstract = {No abstract available}, subject = {Organische Chemie}, language = {en} } @article{StaikovaPericEngelsetal.1994, author = {Staikova, M. and Peric, M. and Engels, Bernd and Peyerimhoff, S. D.}, title = {Ab initio Investigation of the Structure of the X\(^2\)A', A\(^2\)A'' (1\(^2\)Π) Spectral System of HCO: Investigation of the Magnetic Hyperfine Effects}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59089}, year = {1994}, abstract = {Results ofan ab initio study ofthe hyperfine structure of the X\(^2\)A', A\(^2\) A" ( 1\(^2 \Pi\)) system ofthe formyl radical are presented. Special attention is paid to the analysis of the interplay between the vibronic and magnetic hyperfine etfects. The results of computations are in very good agreement with the available experimental findings. The values for the hyperfine coupling constants in lower bending Ievels of both electronic species are predicted.}, subject = {Organische Chemie}, language = {en} } @article{PericEngelsPeyerimhoff1991, author = {Peric, M. and Engels, Bernd and Peyerimhoff, S.D.}, title = {Ab initio investigation of the vibronic structure of the C\(_2\)H spectrum Calculation of the hyperfine coupling constants for the three lowest lying electronic states}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58901}, year = {1991}, abstract = {The hyperfine coupling constants (isotropic hfcc and four Cartesian components of the ani~ tropic tensor) are calculated for all three atoms of C\(_2\)H in its three lowest-lying electronic states at various molecu)ar geometries by means of the ab initio configuration interaction ( MRO.CI) method. The off-diagonal electronic matrix elements involving the two species ofthe A' symmetry are also computed. A diabatic transforrnation is perforrned Jeading to simple geometrical depen· dences of the hyperline coupling constants.}, subject = {Organische Chemie}, language = {en} } @article{PericEngelsPeyerimhoff1991, author = {Peric, M. and Engels, Bernd and Peyerimhoff, S.D.}, title = {Ab initio investigation of the vibronic structure of the C\(_2\)H spectrum Computation of the vibronically-averaged values for the Hyperfine Coupling Constants}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58915}, year = {1991}, abstract = {The vibronically averaged values for tbe hyperfine coupling constants in the X\(^2 \sum\)-A\(^2 \Pi\) system of the ethynyl radical are computed by means of tbe ab initio metbod calculations. The results point at tbe importance of taking into account the coupling of a1l tbree electronic states in question ( I\(^2\)A', 2\(^2\)A', and 1\(^2\)A") for a reliable explanation of the available experimental findings. The mean values of the hfcc's for K = 0 and 1 levels in \(^{13}\)C\(_2\)H and \(^{13}\)C\(_2\)D in the energy range up to 6000 cm\(^{-1}\) are predicted.}, subject = {Organische Chemie}, language = {en} } @article{EngelsPericReuteretal.1992, author = {Engels, Bernd and Peric, M. and Reuter, W. and Peyerimhoff, S.D. and Grein, F.}, title = {Study of the hyperfine coupling constants \(^{14}\)N and \(^1\)H) of the NH\(_2\) molecule in the X\(^2\)B\(_1\) ground state and the A\(^2\)A\(_1\) excited state}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58937}, year = {1992}, abstract = {The hyperfine coupling constants (hfcc) A\(_{iso}\) and A\(_{ij}\) are calculated for the atoms of NH\(_2\) in its, two lowest-lying electronk states at various molecular geometries by means of the ab initio multireference configuration interaction .method. The vibronically averaged values of the hfccs for the K = 0 and 1 levels in \(^{14}\)N \(^1\)H\(_2\) in the energy range up to 20 000 cm\(^{-1}\) are computed. Polarization elfects which determine A\(_{iso}\) as well as a simple model to describe the dipolar hfccs are discussed. All resrilts are in excellent agreement with experimental data.}, subject = {Organische Chemie}, language = {en} }