ENERGETIC COLLISIONS OF CHARGED PROJECTILES WITH ATOMIC BOUND-STATES

Use of the multiple-scattering expansion of the three-body amplitude f or atomic direct and exchange reactions requires the evaluation of mul tidimensional integrals involving the two-body Coulomb T-operator. We present here numerical results for the first-order terms, both for the attractive and repulsive case. Furthermore, easy-to-calculate approxi mations are described which in their domain of validity (i) reproduce the exact amplitudes to high accuracy, and (ii) also serve to derive i nteresting theoretical results.