AB-INITIO CHEMICAL-KINETICS - CONVERGED QUANTAL REACTION-RATE CONSTANTS FOR THE D-2 SYSTEM(H)

We present accurate quantal rate constants for the D + H-2 system in t he 167-900 K temperature range and rate constants calculated in the se parable rotation approximation up to 1500 K. We have calculated rate c onstants for the three most accurate ab initio potential energy surfac es. The separable-rotation calculations agree to within 2.2% with the present accurate quantal calculations, and the results show substantia lly better agreement with high-temperature experimental rate constants than do previous quantal calculations. The ab initio rate constants f or the LSTH and DMBE surfaces agree well with experiment over a wide t emperature range; but the newer BKMP surface gives poor agreement at l ow temperatures. From 200 to 900 K, a factor of 4.5 in temperature, th e present totally ab initio reaction rate constants agree with experim ent within 13% or better at each temperature, with an average absolute deviation of only 5%.