D+D2 QUASI-CLASSICAL RATE-CONSTANT CALCULATIONS ON PARALLEL COMPUTERS

The calculation of rate constant values of the H + H2 reaction for an extended range of excited vibrational states of the diatomic molecule and temperatures is relevant to the modeling of H- sources. To investigate the effect of isotopic substitutions on the efficiency of vibrational deexcitation processes, we extended the calculations to the D + D2 system. These calculations were carried out using a program restructured to run on a shared memory vector and parallel computer. The dependence of the efficiency of vibrational deexcitation processes from both the initial vibrational state and temperature of reactants is reported. Restructuring strategies adopted for implementing the program on both shared and distributed memory computers as well as speedups achieved on both types of machines are also discussed.