We have been especially interested in global coupled PESs of small atmospheric molecules due to their significant role in determining thermal energy content and heat flux in the flows around hypersonic vehicles. For example, the exothermic recombination of atomic oxygen on the surface of vehicles contributes to heat shield erosion. Among the open questions are if and when electronically excited species of O2 and O may be generated and to what extent these high-energy excited species affect the species concentrations, state populations, chemical reactions, energy relaxation, and heat balance of the ultrahightemperature environment in the strong shock waves. Electronically nonadiabatic dynamics simulations (i.e., simulations in which the electronic state changes) of O + O 2 collisions can be valuable in addressing this question. The starting point for such simulations is a set of analytic representations of the dense manifolds of global coupled PESs of O3 in the various electronic symmetries.