Full-dimensional quantum dynamics study of exchange processes for the D + H2O and D + HOD reactions.
Full-dimensional quantum dynamics study of exchange processes for the D + H2O and D + HOD reactions.
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DOI：
10.1063/1.4718386
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发表时间：
2012-05
期刊：
影响因子：
--
通讯作者：
Bina Fu;Dong H. Zhang
中科院分区：
文献类型：
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作者：
Bina Fu;Dong H. Zhang
采用全维初始状态选择时变波包方法研究了D + H(2)O和D + HOD反应的交换过程。通过离心突然近似和精确耦合通道计算，得到了H(2)O（HOD）反应物初始处于地震动状态时，不同部分波的总反应概率和积分截面。在CC计算中，反应概率中的小共振峰和随着总角动量J的增加而迅速减弱的共振峰不会导致标题反应截面上刚好高于阈值的明显阶梯状特征，这与其他同位素取代反应中以氢原子代替氘原子作为反应物不同[B]。周勇，张德华，傅玉华，化学。科学3,270 (2012)；傅斌，张德华，物理学家。化学。A 116, 820(2012)]。有趣的是，在氘原子与H(2)O或HOD的反应中，由于试剂氘原子在标题反应中的隧穿能力比其他反应中的试剂氢原子弱，导致反应隧穿引起的形状共振诱导特征相应明显减弱。在CS计算中，共振峰存在于许多部分波中，但不能在部分波求和中存活。D(') + H(2)O→D(')OH + H和D(') + HOD→D(')OD + H反应的截面比D(') + HOD→HOD(') + D反应的截面大得多，说明D(')/H交换反应比D(')/D交换反应更有利。
The exchange processes of D + H(2)O and D + HOD reactions are studied using initial state-selected time-dependent wave packet approach in full dimension. The total reaction probabilities for different partial waves, together with the integral cross sections, are obtained both by the centrifugal sudden (CS) approximation and exact coupled-channel (CC) calculations, for the H(2)O(HOD) reactant initially in the ground rovibrational state. In the CC calculations, small resonance peaks in the reaction probabilities and quick diminishing of the resonance peaks with the increase of total angular momenta J do not lead to clear step-like features just above the threshold in the cross sections for the title reactions, which are different in other isotopically substituted reactions where the hydrogen atom was included as the reactant instead of the deuterium atom [B. Fu, Y. Zhou, and D. H. Zhang, Chem. Sci. 3, 270 (2012); B. Fu and D. H. Zhang, J. Phys. Chem. A 116, 820 (2012)]. It is interesting that the shape resonance-induced features resulting from the reaction tunneling are significantly diminished accordingly in the reactions of the deuterium atom and H(2)O or HOD, owing to the weaker tunneling capability of the reagent deuterium atom in the title reactions than the reagent hydrogen atom in other reactions. In the CS calculations, the resonance peaks persist in many partial waves but cannot survive the partial-wave summations. The cross sections for the D(') + H(2)O → D(')OH + H and D(') + HOD → D(')OD + H reactions are substantially larger than those for the D(') + HOD → HOD(') + D reaction, indicating that the D(')/H exchange reactions are much more favored than the D(')/D exchange.