Electronic structure and dynamics in the O4 system

There has been a renewed interest in the properties of the O4 system in recent years coming from a variety of scientific fields(high resolution spectroscopy, nature of intermolecular forces, molecular beam scattering, molecular collision dynamics, photochemistry, atmospheric chemistry, solid state physics) and aimed at a better understanding of its electronic structure and dynamics. In this contribution I will review our current knowledge of this system with particular emphasis on the electronic structure and dynamics of the O2(v very much greater than 0) + O2(v=0) collision which we have been studying in the past several years and is still the subject of debate stemming from unsolved discrepancies between theory and experiment and also its possible relevance in determining the chemical composition of the atmosphere.