PARALLEL CALCULATIONS OF APPROXIMATE 3D-QUANTUM CROSS-SECTIONS - THE LI + HF REACTION

Our reactive-infinite-order-sudden-approximation (RIOSA) numerical procedure has been revisited to single out features relevant to the parallel restructuring. Speedups obtained on a shared-memory machine, after a restructuring aimed at exploiting both the temporal and spatial parallelism of the approach, are discussed. Saved computer time has been invested in improving the theoretical approach and enriching the detail of the calculated quantities. As an application, an extensive calculation of the reactive cross section of the Li + HF system has been carried out on a potential energy surface modified according to the indications of a recent ab initio calculation. Preliminary results of a testing of the program on a distributed-memory computer architecture, are also given.