Carbon suboxide: The vibrational dependence of the ν7 bending potential function

Data on the vibrational energy levels and rotational constants of carbon suboxide for the low-wavenumber bending mode ν₇ are reviewed, in the ground-state manifold, and in the ν₂-, ν₃-, ν₄-, and ν₂ + ν₄-state manifolds. Following the procedure developed by Duckett, Mills, and Robiette J. Mol. Spectrosc.63, 249 (1976)] the data have been inverted to give the effective bending potential in ν₇ for each of these five states. Values are obtained for various other parameters in the effective vibration-rotation Hamiltonian. The potential and rotational constants in ν₂ + ν₄ are given to a close approximation by linear extrapolation from the ground state through the ν₂ and ν₄ states.