原子与双原子分子碰撞过程的量子力学研究

2019-01-27 09:51:06

He potential 原子 calculated 势能









中文题名原子与双原子分子碰撞过程的量子力学研究

 





副题名 





外文题名 





论文作者孙桂华   





导师杨向东教授   





学科专业原子与分子物理   





研究领域\研究方向原子分子碰撞   





学位级别博士 





学位授予单位四川大学   





学位授予日期2002   





论文页码总数124页   





关键词量子力学  双原子分子  原子  势能面  散射截面   





馆藏号BSLW

/2003

/O562

/2 





【中文摘要】

    本文分两部分:第一部分用三维量子力学耦合通道扭曲波方法研究了三氢系统的反应散射;第二部分提出了一种原子与双原子分子相互作用的新形式。
   在第一部分,我们用三维量子力学的耦合通道扭曲波近似法(CCDWA)研究了反应散射H+H〓→H〓+H、D+H〓→DH+H、H+D〓→DH+D。计算中采用了LSTH、BKMP和PK三种势能面,计算了三个碰撞体系的积分截面、微分截面、分波截面和反应几率。研究发现:势能面相同时用CCDWA方法计算的截面和公认精确的量子力学结果比较符合;阈能附近的量子力学隧道效应较为显著,准经典弹道方法不能很好的预言其截面;用不同势能面计算的反应截面有差别,说明反应截面的研究能为检验势能面的准确性提供依据。
   在第二部分,我们首先改进了MS(Maitland-Smith)势能模型,改进的势能模型具有表达函数简单、可调参数少、形式灵活、便于应用等优点。其次,根据改进的势能模型分别给出了He-HF和He-CO系统新的各向异性势能面,新的势能面与它们准确性较好的SAPT势(He-HF)、XC势(He-CO)非常相似,能比较准确地描述He-HF、He-CO体系相互作用势的基本特征。第三,根据MS势模型给出了He-NO系统的各向异性势能面,该势能面不仅与He-NO较准确的势能面ESMSV符合较好,而且与其它惰性气体原子(Ar、Kr、Xe)与NO分子的MS势具有相同的形式和部分势能参数。最后利用改进的势能模型给出了Faubel等关于He-O〓相互作用势径向系数计算值的解析表达式,用这个表达式计算的结果与Faubel等的计算值比较一致。











【外文摘要】

 Abstract
   There are two parts in this dissertation. In part one, the reaction scattering for the H〓 system is studied using three-dimensional quantum mechanical coupled channel distorted wave approximation. In part two, a new form is proposed for interaction between an atom and a diatomic molecule.
   Using three-dimensional quantum mechanical coupled channel distorted wave approximation (CCDWA) , the reaction scattering H+H〓→H〓+H, D+H〓→DH+H, H+D〓→DH+D are studied by employing the three potential energy surfaces, i. e. LSTH, BKMP and PK in part one. The integral, differential, partial wave cross sections and reaction probabilities are calculated for the three collision systems. It is shown that the results calculated using the CCDWA are agreement with one of the accurate quantum mechanics employing the same potential. Quantum mechanical tunneling is important in near threshold, and classical trajectory calculation is not good for prediction of the cross sections. The reaction cross sections calculated using different potentials is different, which show that the investigation of reaction cross section can provide evidence for test of accuracy of the potential energy surface.
   Firstly, the MS (Maitland-Smith) potential model is improved in part two. The model possesses advantages of the simpler functional representation, the fewer adjustable parameters, the more flexible form, and it is easy to apply. Secondly, the new anisotropic potential energy surfaces are proposed for the He-HF and He-CO systems respectively based on the improved potential model. The potentials are very similar to the accurate SAPT (for the He-HF) and XC (for the He-CO) potentials and can describe exactly the basic characteristic of interaction for the systems. Thirdly, a new anisotropic potential energy surface is presented for the He-NO system according to the MS potential model. The potential is not only quite agreement with the accurate ESMSV potential for the system, but also has the same form and part parameters for the MS potentials of other rare gases (Ar, Kr, Xe) with NO molecule. Finally, an analytical expression is given out using the improved potential model based on Faubel's calculated data of radial coefficients of interaction for the He-O〓 system, the results calculated using the analytical expression is quite agreement with Faubel's calculated data.