A new method for calculating angular integrals in electron—atom scattering Original Research Article

This paper reports a novel method for calculating certain angular integrals that occur in the matrix elements of the Hamiltonian which describes the scattering of an electron by a complex atom or ion. Specifically the method applies to those matrix elements which involve the quadratically integrable terms, the so-called bound—bound and bound—continuum matrix elements. It considerably reduces the number of integrals which need to be calculated giving an appreciable speed-up in the calculation for low values of the total orbital angular momentum. The application of the method to a data decomposition parallelization scheme for the construction of the Hamiltonian matrix is discussed.