Communication: Multistate quantum dynamics of photodissociation of carbon dioxide between 120 nm and 160 nm
- Department of Chemistry, Technical University of Munich, Lichtenbergstr. 4, 85747 Garching (Germany)
UV absorption cross section of CO{sub 2} is studied using high level ab initio quantum chemistry for electrons and iterative quantum dynamics for nuclear motion on interacting global full dimensional potential energy surfaces. Six electronic states-1, 2, 3{sup 1}A{sup Prime} and 1, 2, 3{sup 1}A{sup Double-Prime }-are considered. At linearity, they correspond to the ground electronic state X(tilde sign){sup 1}{Sigma}{sub g}{sup +} and the optically forbidden but vibronically allowed valence states 1{sup 1}{Delta}{sub u}, 1{sup 1}{Sigma}{sub u}{sup -}, and 1{sup 1}{Pi}{sub g}. In the Franck-Condon region, these states interact via Renner-Teller and conical intersections and are simultaneously involved in an intricate network of non-adiabatic couplings. The absorption spectrum, calculated for many rotational states, reproduces the distinct two-band shape of the experimental spectrum measured at 190 K and the characteristic patterns of the diffuse structures in each band. Quantum dynamics unravel the relative importance of different vibronic mechanisms, while metastable resonance states, underlying the diffuse structures, provide dynamically based vibronic assignments of individual lines.
- OSTI ID:
- 22098913
- Journal Information:
- Journal of Chemical Physics, Vol. 137, Issue 2; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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