Quantum dynamics of the C(D1)+HD and C(D1)+n−D2 reactions on the ã A1′ and b̃ A1″ surfaces

We present the Born–Oppenheimer, quantum dynamics of the reactions C(D1)+HD andC(D1)+n−D2 on the uncoupled potential energy surfaces a A1′ and b A1″, considering the Coriolis interactions and the nuclear-spin statistics. Using the real wavepacket method, we obtain initial-state-resolved probabilities, cross sections, isotopic branching ratios, and rate constants. Similarly to the C+n−H2 reaction, the probabilities present many a A1′ or few b A1″ sharp resonances, and the cross sections are very large at small collision energies and decrease at higher energies. At any initial condition, the C+HD reaction gives preferentially the CD+H products. Thermal cross sections, isotopic branching ratios, and rate constant k vary slightly with temperature and agree very well with the experimental values. At 300 K, we obtain for the various products k(CH+H)=(2.45±0.08)×10−10, k(CD+H)=(1.19±0.04)×10−10, k(CH+D)=(0.71±0.02)×10−10, k(CD+D)=(1.59±0.05)×10−10 cm3 s−1, and k(CD+H)/k(CH+D)=1.68±0.01. The b A1″ contributi...