Dick, Bernhard and Hohlneicher, Georg
Two-photon spectroscopy of dipole-forbidden transitions. I. Dipole-forbidden transitions and double excited configurations in the CNDO-CI methods.
Theoretica Chimica Acta 53 (3), pp. 221-251.
The applicability was investigated of CNDO/S-type methods for the calcn. of optical spectra of mols. with the special implication that the calcns. should not only describe the intense, dipole-allowed transitions which dominate the 1-photon absorption spectrum but also those transitions which are 1-photon forbidden in 1st order approxn. Such a method is well suited to predict dipole allowed and dipole forbidden transitions at a similar level of accuracy if doubled excited configurations are taken into account. In spite of the lack of perfect pairing in NDO methods there are still 2 types of states which exhibit a different sensitivity towards correlation effects. Therefore, the approxn. used to describe the R-dependence of the Coulomb repulsion gains much more importance than in cases where mainly dipole allowed transitions are of interest. These findings confirm results obtained earlier from theories for which the pairing theorem is valid. The calcd. data show an excellent stability with respect to further increase of the no. of configurations if at least ~200 energy selected configurations are taken into account.
|Additional information (public):||CAN 92:31190
Spectra by Absorption, Emission, Reflection, or Magnetic Resonance, and Other Optical Properties|
|Institutions:|| Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry III - Physical Chemistry (Light and Matter) > Prof. Dr. Bernhard Dick |
|Keywords:||Photon (spectroscopy of 2, of dipole-forbidden transitions, CNDO-CI calcn. of);
Energy level transition (dipole-forbidden, two-photon spectroscopy of, CNDO-CI calcn. of);
Spectrometry (two-photon, of dipole-forbidden transitions, CNDO-CI calcn. of);
dipole forbidden transition spectra;
two photon spectroscopy|
|Subjects:||500 Science > 540 Chemistry & allied sciences|
|Refereed:||Yes, this version has been refereed|
|Created at the University of Regensburg:||No|
|Deposited On:||20 Jan 2009 14:13|
|Last Modified:||17 Jan 2012 10:29|