基于一个新SiH_(2)(1^(1)A′)势能面的H+SiH反应动力学研究  

Quantum dynamics study of reaction H+SiH using a new potential energy surface of SiH_(2)(1^(1)A′)

作　　者：赵文丽[1] 宋玉志[2] 马超 高峰[1] 孟庆田[2] Zhao Wen-Li;Song Yu-Zhi;Ma Chao;Gao Feng;Meng Qing-Tian(College of Information Science and Engineering,Shandong Agricultural University,Taian 271018,China;School of Physics and Electronics,Shandong Normal University,Jinan 250358,China)

机构地区：[1]山东农业大学信息科学与工程学院,泰安271018 [2]山东师范大学物理与电子科学学院,济南250358

出　　处：《物理学报》2024年第20期195-202,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12274265,12104262);山东省自然科学基金(批准号:ZR2022MA087,ZR2022MA006,ZR2020QA051);山东省高等学校“青创团队计划”(批准号:2022KJ240)资助的课题.

摘　　要：本文基于2022年报道的一个SiH_(2)(1^(1)A′)势能面,运用切比雪夫波包方法对H(^(2)S)+SiH(X^(2)П;v=0;j=0)→Si(^(1)D)+H_(2)(X^(1)∑_(g)^(+))反应体系在1:0×10^(-3)-1.0 eV的碰撞能量范围内进行动力学研究.分别应用忽略科里奥利耦合效应的耦合态近似和精确量子力学计算得到该反应的反应概率、积分散射截面和速率常数.计算发现在J较大时,科里奥利耦合效应显著提升该反应的反应概率,忽略科里奥利耦合效应会使H+SiH反应的积分散射截面和速率常数减小,对于速率常数而言,温度越高,两种计算方法所得结果的差距越大.精确的量子力学计算结果表明,H+SiH反应的速率常数在300-1000 K之间几乎不随温度改变,这与H+CH反应非常相似,但是在数值上,前者比后者大1个数量级.Initial state-selected and energy-resolved reaction probabilities,integral cross sections(ICSs),and thermal rate constants of the H(^(2)S)+SiH(X^(2)П;v=0;j=0)→Si(^(1)D)+H_(2)(X^(1)∑_(g)^(+))reaction are calculated within the coupled state(CS)approximation and accurate calculation with full Coriolis coupling(CC)by a time-dependent wave packet propagation method(Chebyshev wave packet method).Therefore,a new ab initio global potential energy surface(PES)of the electronic ground state(1^(1)A′)of the system,which was recently reported by Li et al.[Phys.Chem.Chem.Phys.2022247759],is employed.The contributions of all partial waves to the total angular momentum J=80 for CS approximation and J=90 for CC calculation are considered to obtain the converged ICSs in a collision energy range of 1.0×10^(-3)-1.0 eV.The calculated probabilities and ICSs display a decreasing trend with the increase of the collision energy and show an oscillatory structure due to the SiH_(2) well on the reaction path.The neglect of CC effect will lead to underestimation of the ICS and the rate constant due to the formation of an SiH_(2) complex supported by the stationary points of the SiH_(2)(1^(1)A′)PES.In addition,the results of the exact calculation including CC effect are compared with those calculated in the CS approximation.For the reaction probability,CC and CS calculations change with similar tends,shown by their observations at small total angular momentum J=10,20 and 30,and the CC results are larger than the CS results almost in the whole considered energy range at large total angular momentum J=40,50,60 and 70.The gap between CS and CC probability get more pronounced with increasing of J,which reveals that Coriolis coupling effects become more and more important with J increasing for the title reaction.Moreover,the exact quantum-wave calculations show that the thermal rate constant between 300 K and 1000 K for the title reaction shows a similar temperature independent behavior to that for the H+CH reaction,but the value of the

关 键 词：反应概率 积分散射截面 速率常数 

分 类 号：O643.1[理学—物理化学]