Large-scale quantum mechanical scattering calculations on vector computers

The close-coupling or coupled-channel method for direct solution is discussed in this paper. The method is based on a steady-state description of the scattering process in terms of the time-independent Schroedinger partial different equation. It involves the calculation of large numbers of multi-dimensional integrals and the diagonalization, inversion and multiplication of large matrices, as well as linear-equation solving. Techniques are discussed that are useful for electronically inelastic and reactive collisions. An introduction of the theory is given, and the author's numerical algorithm is described. Details of the inputs of the calculation are analyzed, and vectorizing the program on the Cyber 205 and Cray-1 computers is explained