Possible transformations of the ozone molecule in the presence of water associates

Possible channels of ozone transformations in the atmosphere in the presence of isolated water molecules or water associates were studied by quantum-chemical calculations of model systems comprising ozone and water molecules. The calculations were performed using the multiconfigurational self-consistent field approach in the complete active space, including perturbation theory corrections. The electronic excitation of the ozone molecule coordinated to a water associate should result in the formation of a strongly excited hydrogen peroxide molecule, which easily decomposes to two OH radicals. An alternative, less probable, transformation channel involves the formation of the HO₂ radical and atomic hydrogen. The interaction of the ozone molecule with the OH radical in turn results in the formation of the HO₂ radical and oxygen molecule. The MP2 variant of the one-configuration Möller-Plesset perturbation theory was shown to be inapplicable to describing the HO₄ system.