skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Photoexcitation and Auger decay of the Renner-Teller split C 1s{sup -1} {pi}{sub u}{sup *} state in CO{sub 2}

Journal Article · · Physical Review. A
 [1];  [2];  [1]
  1. Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5151 (United States)
  2. Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States)

The broad ({approx_equal}700 meV) C 1s{yields}{pi}{sub u}{sup *} resonance in the absorption spectrum of CO{sub 2} has been decomposed into contributions from two Renner-Teller split core-excited states with bent and linear equilibrium geometries using resonant Auger spectroscopy. The C 1s{sup -1} {pi}{sup *} excited state was found to decay primarily via participator Auger transitions to the A {sup 2}{pi}{sub u} state of CO{sub 2}{sup +}. Analysis of the vibrational structure in the high-resolution Auger spectra, measured at several photon energies across the broad C 1s{yields}{pi}{sub u}{sup *} resonance, was accomplished using calculated Franck-Condon factors for the electronic excitation and de-excitation processes. Estimations of the geometries of the Renner-Teller split core-excited states were obtained from a comparison of the calculations with the resonant Auger spectra. Transitions to the bent core-excited state were found to contribute to the absorption profile exclusively at the photon energies below the maximum of the C 1s{yields}{pi}{sub u}{sup *} resonance, whereas the linear core-excited state becomes accessible at higher photon energies. The symmetric stretch vibrational progression of the linear core-excited state was identified and assigned. The minimum of the potential energy surface of the C 1s{sup -1}{pi}{sup *} core-excited state at its linear configuration was estimated to be 290.4 eV above the ground vibrational level of the ground electronic state of CO{sub 2}. (c) 2000 The American Physical Society.

OSTI ID:
20217461
Journal Information:
Physical Review. A, Vol. 62, Issue 3; Other Information: PBD: Sep 2000; ISSN 1050-2947
Country of Publication:
United States
Language:
English