title: Dynamics and spectroscopy of CH₂OO excited electronic states.
abstract: The excited states of the Criegee intermediate CH2OO are studied in molecular dynamics simulations using directly potentials from multi-reference perturbation theory (MR-PT2). The photoexcitation of the species is simulated, and trajectories are propagated in time on the excited state. Some of the photoexcitation events lead to direct fragmentation of the molecule, but other trajectories describe at least several vibrations in the excited state, that may terminate by relaxation to the ground electronic state. Limits on the role of non-adiabatic contributions to the process are estimated by two different simulations, one that forces surface-hopping at potential crossings, and another that ignores surface hopping altogether. The effect of non-adiabatic transitions is found to be small. Spectroscopic implications and consequences for the interpretation of experimental results are discussed.
authors.affiliation: Department of Chemistry, University of Helsinki, A.I. Virtasen aukio 1 (P.O. Box 55) FI-00014, Finland and Max-Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany. jaroslaw.kalinowski@cec.mpg.de.
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Kalinowski
authors.affiliation: University of California, Irvine, CA 92697-2025, USA.
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Foreman
authors.affiliation: University of California, Irvine, CA 92697-2025, USA.
authors.forename: Kara M
authors.initials: KM
authors.lastname: Kapnas
authors.affiliation: University of California, Irvine, CA 92697-2025, USA.
authors.forename: Craig
authors.initials: C
authors.lastname: Murray
authors.affiliation: Department of Chemistry, University of Helsinki, A.I. Virtasen aukio 1 (P.O. Box 55) FI-00014, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Räsänen
authors.affiliation: Department of Chemistry, University of Helsinki, A.I. Virtasen aukio 1 (P.O. Box 55) FI-00014, Finland and University of California, Irvine, CA 92697-2025, USA and Institute of Chemistry, Hebrew University, Jerusalem 91904, Israel.
authors.forename: R Benny
authors.initials: RB
authors.lastname: Gerber