Simple theory of diffuse structure in continuous ultraviolet spectra of polyatomic molecules. III. Application to the Wulf--Chappuis band system of ozone

We apply a simple model for the photodissociation absorption spectra of bent symmetric triatomic molecules to the Wulf--Chappuis band system of ozone (10 000--22 000 cm-1 ) to assign the electronic states and the diffuse vibrational bands involved. The conical intersection between the two lowest 1A double-prime states is treated in an approximate way, and the role of the lowest excited triplet states is explored. The results indicate that the Wulf band is probably due to the 3A2 state of ozone which gains intensity through spin--orbit coupling. The 1 1A double-prime (1A2) state gives rise to the featureless red wing of the Chappuis band. Most of the structure in the Chappuis band is reproduced in the model and is due to the 2 1A double-prime (1B1) state as was previously supposed. A more complete treatment of the conical intersection and nonadiabatic effects will be necessary to quantitatively reproduce all features of the experimental spectra