Collect. Czech. Chem. Commun. 2001, 66, 983-990

Theoretical Study of the A2Σ+-X2Π Transition of CCO-

Céline Léonarda, Dietmar Pantenb, Pavel Rosmusb,*, Muriel Wyssc and John P. Maierc

a Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
b Theoretical Chemistry Group, Université de Marne-la-Vallée, F-77454 Champs-sur-Marne, France
c Institute for Physical Chemistry, University of Basel, CH-4056 Basel, Switzerland


Three-dimensional potential energy functions have been generated for the A2Σ+ electronic state of C2O- using highly correlated electronic multi-reference configuration interaction wavefunctions. These were employed in variational calculations of the rovibrational states. The rotational constant has been calculated as Be = 0.3960 cm-1, with ReCO = 1.240 Å and ReCC = 1.244 Å. Rovibrational levels for J = 0 and 1 are reported for energies up to about 4 800 cm-1. Only weak anharmonic resonances are found in this energy region. The theoretically predicted A2Σ+←X2Π absorption spectrum is found to be in excellent agreement with the observed one in a neon matrix.

Keywords: Electronic calculations; Vibrational levels variational calculations; Electronic transition; Franck-Condon approximation; Electronic absorption spectroscopy; Vibrational wavefunctions; Ab initio calculations.

References: 14 live references.