反应物分子初始振动激发对H+CH^+→C^++H_2反应的影响  

Effect of reagent vibrational excitation on reaction of H+CH^+→C^++H_2

作　　者：唐晓平[1] 和小虎[2] 周灿华[3] 杨阳[1] 

机构地区：[1]中国科学院大连化学物理研究所分子反应动力学国家重点实验室,大连116023 [2]太原科技大学应用科学学院物理系,太原030024 [3]中国科学院大连化学物理研究所中国科学院化学激光重点实验室,大连116023

出　　处：《物理学报》2017年第12期100-106,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:21403226;21503226)资助的课题~~

摘　　要：在CH_2^+体系的电子基态势能面上运用准经典轨线方法,研究了当碰撞能E=500 me V时,反应物分子的振动激发对H(~2S)+CH^+(X^1Σ^+)→C+(~2P)+H_2(X1_gΣ^+)反应的反应概率、反应截面和立体动力学性质的影响.分别计算了两矢量相关k-j′的P(θ_r)分布,三矢量相关k-k′-j′的P(φr)分布以及反应产物的四个极化微分截面.结果表明,产物分子转动角动量不仅在Y轴方向有取向效应,还定于Y轴的正方向.并且发现,随着振动量子数的增加,对反应体系产物分布的影响就越明显.The effect of reagent vibrational excitation on the stereodynamical properties of H（2S） ＋ CH＋（X1Σ＋） →C＋（2P） ＋ H2（X1Σ＋g ） reaction is investigated by quasi-classical trajectory method on a globally smooth ab initio po-tential surface of the 2A′ state at a collision energy of 500 meV. The reaction probability and the reaction cross-section are also studied. In the calculation, the vibrational levels of the reactant molecules are taken as v = 0, 1, 3, 5 and j = 0, respectively, where v is the vibrational quantum number and j is the rotational quantum number. The calculation results show that the reaction probability reaches a maximum when v = 1, and then decreases with the vibrational quantum number increasing. The integral cross-section decreases sharply with the increase of vibrational quantum number. The potential distribution P（θr）, the dihedral angle distribution P（φr）, and the polarization-dependent generalized differen-tial cross sections are calculated. P（θr） represents the relation between the reagent relative velocity k and the product rotational angular momentum j′. P（φr） describes the correlation of k-k′-j′, in which k′ is the product reagent relative velocity. The peak of P（θr） is at θr = 90？ and symmetric with respect to 90？, which shows that the product rotational angular momentum vector is strongly aligned along the direction perpendicular to the relative velocity direction. The peak of P（θr） distribution becomes increasingly obvious with the increase of the rotational quantum number. The di-hedral angle distribution P（φr） tends to be asymmetric with respect to the k-k′ scattering plane （or about φr = 180？）, directly reflecting the strong polarization of the product angular momentum for the title reaction. Each curve has two evident peaks at about φr = 90？ and φr = 270？, but the two peak intensities are obviously different, which suggests that j′ is not only aligned, but also strongly orientated along t

关 键 词：立体动力学 准经典轨线方法 矢量相关 

分 类 号：O643.12[理学—物理化学]