Bodo Enrico, Lara Manuel, Gianturco Franco A
Department of Chemistry, University of Rome La Sapienza, Piazzale A. Moro 5, 00185 Rome, Italy.
J Chem Phys. 2006 Jan 28;124(4):044308. doi: 10.1063/1.2155480.
Full quantum dynamics calculations have been carried out for the ionic reaction (4)He(2) (+)+(3)He and state-to-state reactive probabilities have been obtained using both time-dependent and time-independent approaches. An accurate ab initio potential-energy surface has been employed for the present quantum dynamics and the two sets of results are shown to be in agreement with each other. The results for zero total angular momentum suggest a marked presence of atom exchange (isotopic replacement) reaction with probabilities as high as 60%. The reaction probabilities are only weakly dependent on the initial vibrational state of the reactants, while they are slightly more sensitive to the degree of rotational excitation. A brief discussion of the results for selected higher total angular momentum values is also presented, while the l-shifting approximation [S. K. Gray et al., Phys. Chem. Chem. Phys. 1, 1141 (1999)] has been used to provide estimates of the total reaction rates for the title process. Such rates are found to be large enough to possibly become experimentally accessible.
已对离子反应⁴He²⁺ + ³He进行了全量子动力学计算，并使用含时和不含时方法获得了态 - 态反应概率。对于当前的量子动力学，采用了精确的从头算势能面，两组结果显示相互一致。总角动量为零的结果表明存在显著的原子交换（同位素置换）反应，概率高达60%。反应概率仅微弱地依赖于反应物的初始振动态，而对转动激发程度稍敏感。还对选定的较高总角动量值的结果进行了简要讨论，同时使用了l - 移位近似[S. K. Gray等人，《物理化学化学物理》1, 1141 (1999)]来估计标题过程的总反应速率。发现这样的速率足够大，有可能在实验中实现。
