The Quantum Mechanics of Collisions between Diatomic Molecules

The quantum mechanics of collisions between diatomic molecules is discussed. Explicit expressions for the angular transition probabilities are obtained. These expressions are in terms of a set of coefficients which are defined by the asymptotic form of the solutions of a set of coupled differential equations in one variable, the separation of the molecules. The coupled differential equations involve integrals of the intermolecular potential function, which may be of any form. A solution of the coupled differential equations by a perturbation method, which is valid in the case of low-energy collisions, in which transitions occur rarely, is discussed.