title: Peroxyacetyl radical: electronic excitation energies, fundamental vibrational frequencies, and symmetry breaking in the first excited state.
abstract: Peroxyacetyl radical [CH3C(O)O2] is among the most abundant peroxy radicals in the atmosphere and is involved in OH-radical recycling along with peroxyacetyl nitrate formation. Herein, the ground (X̃) and first (Ã) excited state surfaces of cis and trans peroxyacetyl radical are characterized using high-level ab initio methods. Geometries, anharmonic vibrational frequencies, and adiabatic excitation energies extrapolated to the complete basis-set limit are reported from computations with coupled-cluster theory. Excitation of the trans conformer is found to induce a symmetry-breaking conformational change due to second-order Jahn-Teller interactions with higher-lying excited states. Additional benchmark computations are provided to aid future theoretical work on peroxy radicals.
authors: Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA.
authors: Andreas V
authors: AV
authors: Copan
authors: Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA.
authors: Avery E
authors: AE
authors: Wiens
authors: Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA.
authors: Ewa M
authors: EM
authors: Nowara
authors: Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA.
authors: Henry F
authors: HF
authors: Schaefer
authors: Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA.
authors: Jay
authors: J
authors: Agarwal