Formalism for multiple scattering

An exact method for treating multiple collisions is developed. The formalism is valid at all energies and all densities. The multiple scattering formalism is based on the amplitude density function method, which was originally derived for solving single collision problems numerically. The formalism yields a relationship between the total transition matrix due to multiple collisions and the transition matrices due to single collisions. Relations are given for multiple scattering to all orders of a molecule from nonoverlapping fixed scattering centers. The application of the formalism to scattering from a rotor and the necessary approximations which lead to the complete decoupling of the scattering equations are discussed