离散映射格点表象理论与分子阴离子光剥离机理研究

发布时间：2018-01-04 03:32

  本文关键词：离散映射格点表象理论与分子阴离子光剥离机理研究　出处：《大连理工大学》2016年博士论文　论文类型：学位论文

  更多相关文章： 离散格点表象 有限元方法 振转态 薛定谔方程 含时量子波包理论 光剥离电子能谱 过渡态 反应共振 反应机理

【摘要】：本论文发展了有限元映射离散格点表象数值计算方法,模拟了阴离子的光电离过程,解释了气相小分子光剥离电子能谱的实验结果。通过对光电子能谱的研究,我们对分子的电子轨道、振转态和过渡态理论有更深入的了解。主要工作概括如下：(1)提出了可以高效求解薛定谔方程的有限元映射离散格点表象(OFE-DVR)方法。OFE-DVR是一种基于有限元离散格点表象(FE-DVR)的方法,它通过格点映射来优化FE-DVR的格点分布,使之在表征波函数以及求解薛定谔方程时效率更高。为了测试OFE-DVR方法的有效性,我们用它来求解小分子一维及二维薛定谔方程,并与其他被广泛使用的方法(包括FE-DVR.Sinc-DVR、Mapped-Sinc-DVR、Mapped Fourier等)进行比较。比较结果表明通过映射可以显著提高FE-DVR方法的计算效率。具体来说,在求解一维或者二维分子振动问题中,OFE-DVR的效率远远高于Sinc-DVR,与Mapped-Sinc-DVR勺效率几乎相同;在求解涉及到库仑奇点的电子波函数问题中,OFE-DVR的效率远远高于其它几种方法。因此OFE-DVR有望在研究电子动力学问题中发挥重要的作用。(2)计算Au2H-、Au2D2-的光剥离电子能谱,并解释了相关的实验结果。通过对Au2H一及其同位素取代物的光剥离实验结果的模拟和分析,我们获得了Au2H-Au2H的电子结构和振转态信息,分析了Au在化学反应中所起的作用。为了计算光剥离电子能谱,我们首先构建了高精度的Au2H-和Au2H从头算势能面。然后利用构建的两个势能面,采用含时量子波包方法计算了Au2H-、Au2D的光剥离电子能谱,其结果与实验数据吻合得很好。基于理论计算,我们对实验结果中的每一个峰都给出了详细的解释,并确定了Au2H-、Au2D-的绝热激发能和垂直激发能,给出了Au2H和Au2D的三个振动模式。(3)采用含时量子波包理论计算了FH2-、FD2-和FHD-的光剥离电子能谱,并与实验结果进行了比较。与计算Au2H-光剥离电子能谱不同的是,计算FH2-光剥离电子能谱主要目的是为了揭示过渡态附近的共振现象对化学反应的影响。为了计算FH2-及其同位素取代物的光剥离电子能谱,我们首先构建了高精度的FH2-从头算势能面。结合原有的高精度的FH2从头算势能面(CSZ势能面),通过用两种不同的方法(FTA方法和FF方法)计算阴离子平衡构型附近的振转态和中性分子本征态之间的弗兰克-康登因子(Frank-Condon Factor)来模拟FH2-及其同位素取代物的光剥离电子能谱。计算结果表明两种不同的方法都能准确地模拟FH2-及其同位素取代物的光剥离电子能谱,并且可以从不同的角度揭示光剥离电子能谱的产生机理,从而让我们对F+H2反应有更全面的理解。另外,我们还把不同势能面(CSZ、SW、FXZ、LWAL)上的计算结果与实验数据进行了全面的比较和分析。结果表明,尽管在这几个势能面上都能得到与实验吻合得很好的理论结果,但是CSZ势能面的计算结果与实验吻合得最好,因此CSZ势能面是目前描述F+H2及其同位素取代物反应最精确的势能面。
[Abstract]:This paper develops a discrete lattice representation mapping finite element numerical calculation method, the simulation process from anion photoelectric, explain the experimental results of gas phase molecular photodetached electron spectrum. Through the study on the photoelectron spectra, we on the molecular electronic track, rovibrational states and transition state theory deeply understand. Main works are summarized as follows: (1) put forward the finite element mapping discrete lattice efficient solution of Schrodinger equation can be the representation of (OFE-DVR).OFE-DVR is a finite element method based on discrete lattice representation (FE-DVR) method, it is through the lattice point mapping to optimize FE-DVR lattice distribution, the characterization of wave the function and solution of Schrodinger equation when higher efficiency. In order to test the effectiveness of the OFE-DVR method, we use it to solve small molecules in one-dimensional and two-dimensional Schrodinger equation, and other widely used methods (including FE-DVR.Sinc-DVR Mapped-Sinc-DVR, Mapped, Fourier) were compared. The comparison results show that the mapping can significantly improve the computational efficiency of FE-DVR method. Specifically, in solving the one-dimensional or two-dimensional molecular vibration problems, the efficiency of OFE-DVR is much higher than that of Sinc-DVR, and the Mapped-Sinc-DVR is almost the same efficiency; relates to the electronic wave function of the Coulomb singularity in the solution. The efficiency of OFE-DVR is much higher than other methods. Therefore OFE-DVR is expected to be in the study of electron dynamics play an important role in the calculation of Au2H-. (2), photodetached electronic Au2D2- energy spectrum, and explains the related experimental results. The simulation and analysis of the photodetachment experiments for Au2H and isotopic substitution, we the electronic structure and vibration Au2H-Au2H transition information, analysis of Au in chemical reaction. In order to calculate the photodetached electron energy spectrum, we Firstly, the high accuracy of Au2H- and Au2H. Then using the ab initio potential energy surface of two potential energy surface construction, the time-dependent quantum wave packet method to calculate the Au2H- and Au2D of the photodetached electronic energy spectrum, and the results are in good agreement with experimental data. Based on the theoretical calculation, the experimental node of each peak results are given a detailed explanation, and to determine the Au2H-, excitation energies and vertical excitation energies of Au2D- adiabatic, gives three vibration modes of Au2H and Au2D. (3) using the time-dependent quantum wave packet theory to calculate the FH2-, FD2- and FHD- of the photodetached electronic energy spectrum, and compared with the the experimental results and calculation of Au2H-. The photodetachment spectrum is different, calculation of FH2- photodetached electronic energy spectrum of the main purpose is to reveal the effect of the transition state near the resonance phenomenon of chemical reaction. In order to photodetached electronic computing and FH2- isotopic substitution energy spectrum, we first To construct high accuracy FH2- ab initio potential energy surface. Combined with the original high precision FH2 ab initio PES (CSZ PES), by using two different methods (FTA method and FF method) to calculate near anionic equilibrium configuration of rovibrational states and neutral molecules between the eigenstates of the Frank - Condon factor (Frank-Condon Factor) to simulate the FH2- and its isotopic substitution photodetached electron spectrum. The calculation results show that the photodetachment of two different methods can accurately simulate the FH2- isotopic substitution energy spectrum, and from different angles to reveal the generation mechanism of photodetached electron energy spectrum, so that we have a more comprehensive understanding of the F+H2 reaction. In addition, we also have different potential energy surfaces (CSZ, SW, FXZ, LWAL) on the calculation results and the experimental data are compared and analyzed. The results show that in spite of these PES can The theoretical results which are in good agreement with the experiment are obtained, but the calculated results of CSZ potential energy surface agree best with the experiment. Therefore, the CSZ potential energy surface is the most accurate potential energy surface to describe the reaction of F+H2 and its isotopic substituents.

【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O561
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本文编号：1376852