Many-body Expansion Potential Function for Ground-state N₂O₂

A many-body expansion potential function in the approximation of sigle-value surf see has been derived from the experimental results of equilibrium configuration, dissociation energy and vibrational frequences of cis-N₂O₂ molecule for the ground-state N₂O₂, which can describe correctly its dissociation limits and represent the exchange symmetry of two equivalent atoms,From this surface, the characters of reactive collision of an excited oxygen atom O（¹D） with a N₂O molecule were discussed. The results show that there are a potential barrier on the exitance as well as a well on the reaction path from reactant O（¹D）+N₂O（X¹Σ） to product 2NO（X²Πr）.