本文關(guān)鍵詞：離散映射格點表象理論與分子陰離子光剝離機理研究　出處：《大連理工大學(xué)》2016年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 離散格點表象 有限元方法 振轉(zhuǎn)態(tài) 薛定諤方程 含時量子波包理論 光剝離電子能譜 過渡態(tài) 反應(yīng)共振 反應(yīng)機理

【摘要】：本論文發(fā)展了有限元映射離散格點表象數(shù)值計算方法,模擬了陰離子的光電離過程,解釋了氣相小分子光剝離電子能譜的實驗結(jié)果。通過對光電子能譜的研究,我們對分子的電子軌道、振轉(zhuǎn)態(tài)和過渡態(tài)理論有更深入的了解。主要工作概括如下：(1)提出了可以高效求解薛定諤方程的有限元映射離散格點表象(OFE-DVR)方法。OFE-DVR是一種基于有限元離散格點表象(FE-DVR)的方法,它通過格點映射來優(yōu)化FE-DVR的格點分布,使之在表征波函數(shù)以及求解薛定諤方程時效率更高。為了測試OFE-DVR方法的有效性,我們用它來求解小分子一維及二維薛定諤方程,并與其他被廣泛使用的方法(包括FE-DVR.Sinc-DVR、Mapped-Sinc-DVR、Mapped Fourier等)進行比較。比較結(jié)果表明通過映射可以顯著提高FE-DVR方法的計算效率。具體來說,在求解一維或者二維分子振動問題中,OFE-DVR的效率遠(yuǎn)遠(yuǎn)高于Sinc-DVR,與Mapped-Sinc-DVR勺效率幾乎相同;在求解涉及到庫侖奇點的電子波函數(shù)問題中,OFE-DVR的效率遠(yuǎn)遠(yuǎn)高于其它幾種方法。因此OFE-DVR有望在研究電子動力學(xué)問題中發(fā)揮重要的作用。(2)計算Au2H-、Au2D2-的光剝離電子能譜,并解釋了相關(guān)的實驗結(jié)果。通過對Au2H一及其同位素取代物的光剝離實驗結(jié)果的模擬和分析,我們獲得了Au2H-Au2H的電子結(jié)構(gòu)和振轉(zhuǎn)態(tài)信息,分析了Au在化學(xué)反應(yīng)中所起的作用。為了計算光剝離電子能譜,我們首先構(gòu)建了高精度的Au2H-和Au2H從頭算勢能面。然后利用構(gòu)建的兩個勢能面,采用含時量子波包方法計算了Au2H-、Au2D的光剝離電子能譜,其結(jié)果與實驗數(shù)據(jù)吻合得很好�；诶碚撚嬎�,我們對實驗結(jié)果中的每一個峰都給出了詳細(xì)的解釋,并確定了Au2H-、Au2D-的絕熱激發(fā)能和垂直激發(fā)能,給出了Au2H和Au2D的三個振動模式。(3)采用含時量子波包理論計算了FH2-、FD2-和FHD-的光剝離電子能譜,并與實驗結(jié)果進行了比較。與計算Au2H-光剝離電子能譜不同的是,計算FH2-光剝離電子能譜主要目的是為了揭示過渡態(tài)附近的共振現(xiàn)象對化學(xué)反應(yīng)的影響。為了計算FH2-及其同位素取代物的光剝離電子能譜,我們首先構(gòu)建了高精度的FH2-從頭算勢能面。結(jié)合原有的高精度的FH2從頭算勢能面(CSZ勢能面),通過用兩種不同的方法(FTA方法和FF方法)計算陰離子平衡構(gòu)型附近的振轉(zhuǎn)態(tài)和中性分子本征態(tài)之間的弗蘭克-康登因子(Frank-Condon Factor)來模擬FH2-及其同位素取代物的光剝離電子能譜。計算結(jié)果表明兩種不同的方法都能準(zhǔn)確地模擬FH2-及其同位素取代物的光剝離電子能譜,并且可以從不同的角度揭示光剝離電子能譜的產(chǎn)生機理,從而讓我們對F+H2反應(yīng)有更全面的理解。另外,我們還把不同勢能面(CSZ、SW、FXZ、LWAL)上的計算結(jié)果與實驗數(shù)據(jù)進行了全面的比較和分析。結(jié)果表明,盡管在這幾個勢能面上都能得到與實驗吻合得很好的理論結(jié)果,但是CSZ勢能面的計算結(jié)果與實驗吻合得最好,因此CSZ勢能面是目前描述F+H2及其同位素取代物反應(yīng)最精確的勢能面。
[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.

【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：O561
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本文編號：1376852