A refined near-equilibrium potential energy surface and the absorption spectrum of OClO(Ã 2A2)

We report a refined near-equilibrium potential energy function for the first excited electronic state (Ã 2A2) of OClO based on a recent ab initio calculation. The potential parameters are adjusted to fit the available experimental vibrational frequencies using a variational method. Excited vibrational wavefunctions are found to have significant amplitudes in non-C2v molecular geometry, despite the fact that the potential has a single C2v minimum. Due to the strong coupling between the symmetric and anti-symmetric stretching coordinates, the vibration in the latter mode is highly anharmonic. The calculated absorption spectrum of the Ã←X̃ transition indicates activities in all three vibrational modes, in agreement with experimental observations.