使用态-态分辨的量子波包方法对Li+HF/DF反应的研究

使用基于反应物坐标的含时量子波包方法，在APW势能面上，计算了碰撞能在0～0.25 eV范围的Li+HF/DF(v=0，j=0，1)反应的积分和微分截面．同时也计算了初始态选择的反应速率常数．计算结果表明，Li+DF和Li+HF反应产物分布基本类似，只是前者产物转动激发态稍微多些．反应物的转动激发对于Li+DF反应影响很小．这两个反应的微分截面都是前向散射为主的，特别是在碰撞能较高时候．产物振转态分辨的积分截面和后向散射随碰撞能而呈现的振荡现象，可以用来指认Li+HF反应中的共振态．Li+HF的反应速率常数在100～300 K几乎不变，而Li+DF的反应速率常数则增长了10倍左右．Li+HF的反应几率和积分截面和以前报道的结果总体符合较好，差别应该是计算收敛性更好所致．

Quantum Dynamics of Li+HF/DF Reaction Investigated by a State-to-State Time-dependent Wave Packet Approach

Using the reactant coordinate based time-dependent wave packet method, on the APW potential energy surface, the differential and integral cross sections of the Li+DF/HF(v=0, j=0, 1) reactions were calculated over the collision energy range from the threshold to 0.25 eV. The initial state-specified reaction rate constants of the title reaction were also calculated. The results indicate that, compared with the Li+DF reaction, the product LiF of Li+HF reaction is a little more rotationally excited but essentially similar. The initial rotational excitation from j=0 to 1 has little effect on the Li+DF reaction. However, the rotational excitation of DF does result in a little more rotationally excited product LiF. The different cross section of both reactions is forward biased in the studied collision energy range, especially at relatively high collision energy. The resonances in the Li+HF reaction may be identifiable as the oscillations in the product ro-vibrational state-resolved integral cross sections and backward scattering as a function of collusion energy. For the Li+HF reaction, the rate constant is not sensitive to the temperature and almost has no change in the temperature range considered. For the Li+DF reaction, the rate constant increase by a factor of about 10 in the temperature range of 100?300 K. Brief comparison for the total reaction probabilities and integral cross section of the Li+HF reaction has been carried out between ours and the values reported previously. The agreement is good, and the difference should come from the better convergence of our present calculations.