On the Inelastic Collision between Molecules, II: Rotational Transition of H2-molecule in the Collision with another H2-molecule

In this paper we consider the rotational transition of H2-molecule in the collision with another H2-molecule. The general derivation of the cross section and an example of the numerical calculation by a simplified method of approximation are presented. The result is compared with experimental value of the transition rate in H2 gas obtained from the anomalous dispersion of the supersonic wave. The agreement of the calculated and the experimental rates is found to be within factor 2, and this is better than is expected under the accuracy of the approximation employed and also under the present situation concerning the knowledge of the intermolecular force.