Abstract
Collisions between ground state N atoms and O2 molecules are of three distinct types. These correspond to doublet, quartet, and sextet states of the collision complex. Potentials operative in the doublet and quartet collisions are computed by the diatomics‐in‐molecules method. Analysis of these potentials suggests reaction occurs only through the quartet collisions. The experimentally observed activation energy is found to arise from dynamic considerations on the barrierless surface.