DTO体系分子反应动力学

Theoretical study on molecular reaction dynamics of the DTO system

基于DTO分子（X^-1A1）的氢同位素效应，得到修正的Born-Oppenheimer（B-O）理论下多体展式分析势能函数．用准经典的Monte-Carlo轨迹法研究了D＋TO（0，0）和T＋DO（0，0）的分子反应动力学过程．结果表明：在碰撞能量较低时（〈209．2kJ·mol^-1），D＋TO（0，0）和T＋DO（0，0）反应主要生成O＋DT，并且该反应是无阈能的；有少量的交换反应产物DO（TO）生成，并伴有极少量的络合物产生．碰撞能大于209．2kJ·mol^-1后，逐渐出现分子被完全碰散成D，T，O原子的情形．反应D＋TO（0，0）→OD＋T和T＋DO（0，0）→OT＋D是无热反应但是有阈能存在．由于D和T原子的同位素效应，置换产物轨线存在非一致性．

Based on the hydrogen isotopic effect and its nuclear motion, the analytical potential energy function （APEF） of DTO （ X^-1A1）is derived by many-body expansion method （MEM） under the correctional Born- Oppenheimer （B-O）. Then the atomic and molecular reaction dynamics for D ＋ TO and T ＋ DO have been studied on the potential energy function DTO （ X^-1A1 ） by Monte-Carlo quasi-classical trajectory approach. It is shown that the main reactions of D ＋ TO→DT ＋ O and T ＋ DO→DT ＋ O along with a few long-lived complex compounds have no threshold energy with low collision energy, which agrees with the potential surface. When the collision energy is greater than 209.2 kJ· mol-^ 1, the DTO molecules will decompose into D, T and O atom completely, and these reactions have threshold energy. The other reactions of D ＋ TO→TO ＋ D and T ＋ DO→DO ＋ T are the reactions of non-decalescence, but they have threshold energy. However, the trajectories and collision sections of reactions D ＋ TO （0,0） and T ＋ DO （0,0） present variance distribution due to the isotopic effect of deuterium and tritium atom,which corresponds to the potential surface.