Abstract
The mechanism to explain the afterglow in the collision of H((2)S) and NO((2)Π) is critically examined by calculating part of the energy surface of the (3)A″ state. It is found that the long range interaction energies are consistently repulsive even though at shorter distances attractive ionic interactions dominate. It is concluded that the essential feature of the Clyne and Thrush mechanism is missing; intimate interaction of H((2)S) and NO((2)Π) is not possible at room temperature along the (3)A″ surface. This study was undertaken to provide an example where a theoretical calculation is required to critically test a kinetics mechanism.