【摘要】 首次构造了放热反应Ba +HF(v ,J)→BaF(v′ ,J′) +H的LEPS势能面 ,并且进行了准经典轨线研究 .对于初始基态 ,和初始第一激发态的反应物HF ,计算得到的BaF产物态分布与实验吻合得比较好 .对产物取向的研究表明 ,反应体系的质量组合是产物取向的决定因素 .反应过程中 ,直接的提取反应和间接的插入反应是两种竞争的微观反应通道 ,这种竞争是由于在Ba原子进攻HF分子的时候 ,即使进攻方向偏离了HF共线的方向也不会引起能垒高度的明显增加 .而且低的反应物平动能倾向于提取反应而高的HF振动激发会导致插入反应更多还原

【Abstract】 Ba+HF reaction is an interesting example whether for the experiment or theoretical research. But no potential energy surface for this reaction emerges for a long time because of the difficulty of the exact ab initio caused by the large mass number of the Ba atom. The first quasiclassical trajectory calculation for the exothermic reaction Ba+HF ( v,J ) → BaF( v′,J ′)+H is carried out based on a constructed extended LEPS PES. The calculated BaF product state distributions agree closely with experiment for both Ba+HF( v =0) and Ba+HF( v =1) . The reaction mechanism is described as following two pathways, abstraction and insertion, and the small increment of the barrier height along with the attacking deviation from the linear direction (Ba-F-H) is the main cause of this competition. Low collision energy favors abstraction whereas high vibration excitation leads to insertion.更多还原