Electronic structure of carbon trioxide and vibronic interactions involving Jahn-Teller states

Timothy Kowalczyk; Anna I Krylov

doi:10.1021/jp073627d

Electronic structure of carbon trioxide and vibronic interactions involving Jahn-Teller states

J Phys Chem A. 2007 Aug 23;111(33):8271-6. doi: 10.1021/jp073627d. Epub 2007 Jul 28.

Authors

Timothy Kowalczyk¹, Anna I Krylov

Affiliation

¹ Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA.

PMID: 17661455
DOI: 10.1021/jp073627d

Abstract

The electronic structure of CO3 is characterized by equation-of-motion and coupled-cluster methods. C(2v) and D(3h) isomers are considered. Vertical excitation energies, transition dipoles, and the molecular orbital character of the excited states are presented for singlet and triplet manifolds. Ground-state equilibrium structures and frequencies are strongly affected by vibronic interactions with low-lying excited states. At D(3h) geometries, the vibronic interactions are enhanced by the Jahn-Teller character of the excited states. The curvature of the potential energy surface and the existence of the D(3h) minimum are very sensitive to the correlation treatment and the basis set. The correlation effects are stronger at D(3h), in agreement with a smaller HOMO-LUMO gap.