N2价轨道的精细电子动量谱学研究

在高分辨率（ΔE=08?eV,Δp≈01a.u.）高效率的第三代电子动量谱仪上获得了N₂价轨道的电离能谱和动量谱.通过对伴线结构的电子动量谱学（EMS）研究,得到了不同伴线结构的电子动量谱,另一方面也得到了伴线结构的强度.由伴线的电子动量分布形状判断出其跃迁的主要来源,并由实验测量的伴线结构强度确定了谱因子（极强度）的大小,通过对谱因子实验值与理论计算结果的比较检验了各种理论模型的精确度. 关键词： 氮分子 价轨道 电子动量谱 电子关联效应     

丁酮分子内价轨道1a″的电子动量谱学研究

用高分辨率电子动量谱仪进行丁酮分子的结合能谱和内价轨道1a″电子动量谱的实验工作，以及用Hartree-Fock和密度泛函理论方法对1a″轨道电子动量谱的理论研究. 得到了各价轨道的电离能值以及理论计算的总能、偶极矩和1a″轨道的二维密度图. 并比较了内价轨道1a″的电子动量谱的实验和理论计算结果，实验结果与理论计算符合较好.     

丁酮分子内价轨道1a"的电子动量谱学研究

用高分辨率电子动量谱仪进行丁酮分子的结合能谱和内价轨道1a"电子动量谱的实验工作,以及用HartreeFock和密度泛函理论方法对1a"轨道电子动量谱的理论研究.得到了各价轨道的电离能值以及理论计算的总能、偶极矩和1a"轨道的二维密度图.并比较了内价轨道1a"的电子动量谱的实验和理论计算结果,实验结果与理论计算符合较好.     

二乙酰分子内价轨道4ag+4bu的电子动量谱学研究

在高分辨率(△E＝1.15 eV,△p≈0.la.u.)电子动量谱仪上获得了二乙酰分子(diacetyl)最内价轨道4ag+4bu的电离能谱和动量谱的实验结果,并用Hartree-Fock和密度泛函理论方法做了理论计算.实验结果与理论计算符合较好.     

1,3-环己二烯内价分子轨道4a的电子动量谱

在600 eV, 1200 eV, 2400 eV三个入射能下首次实验测量了环己二烯的价壳层电离能谱和内价分子轨道4a的电子动量谱,并将实验结果与密度泛函理论和Hatree-Fock在不同基组下的计算作了比较.     

1，3-环己二烯内价分子轨道4a的电子动量谱

在600 eV，1200 eV，2400 eV三个入射能下首次实验测量了环己二烯的价壳层电离能谱和内价分子轨道4a的电子动量谱，并将实验结果与密度泛函理论和Hatree-Fock在不同基组下的计算作了比较．     

探测二茂铁外价轨道(e,2e)反应中的扭曲波效应

利用第三代高效率电子动量谱仪,分别在600和1500 eV两种不同入射电子能量下获得了二茂铁(ferrocene)分子外价轨道的电离能谱和电子动量谱的相关实验结果.并利用非相对论与标量相对论密度泛函方法计算出了二茂铁的重叠型和交错型两种不同构象的理论动量谱.两种构象的外价轨道一一对应,理论电子动量谱基本一样.对二茂铁的外价轨道,在低动量区观测到了强烈的扭曲波效应,这与这些轨道主要由铁原子的3d轨道构成有关.通过相对论和非相对论计算结果的比较,表明相对论效应对于二茂铁的外轨道动量分布几乎没有影响. 关键词： 二茂铁分子 电子动量谱 相对论效应 扭曲波效应     

环戊酮分子8a1轨道的电子动量谱学研究

首次获得了环戊酮分子8a1轨道的电子动量谱的实验结果,并且给出了价轨道的电离能谱信息.实验用非共面对称几何条件下的能量多道型电子动量谱仪完成,入射电子的能量为1200 eV和600 eV加结合能.Hatree-Fock方法和密度泛函理论计算得到的结果与实验结果作了比较,实验结果和理论计算符合较好.     

苯甲醇分子HOMO和N-HOMO轨道的电子动量谱学研究

利用第三代电子动量谱仪研究了苯甲醇(C_6H_5CH_2OH)分子的最高占据轨道(HOMO)和次最高占据轨道(N-HOMO)电子动量谱,给出了外价轨道的电离能谱信息.实验在非共面对称几何条件下完成,入射电子的能量为2400 eV加结合能.通过密度泛函方法计算得到了苯甲醇分子最高和次最高占据轨道的动量谱,理论与实验结果符合较好.     

SF6电子动量谱学研究中干涉效应的观测

利用非共面对称的高效率(e,2e)电子动量谱仪测量了SF₆分子外价分子轨道的二维电子能量- 动量密度谱. 通过理论计算与实验结果的比较,发现B3LYP密度泛函理论计算结果可以较好地解释实验测量的轨道电子动量分布. 此外,对于最外层的4个来自F2p孤对电子贡献的非键分子轨道,实验上观测到非常明显的多中心干涉图样.     

Experimental and theoretical investigations into the electronic structure of CF2Br2 by electron momentum spectroscopy

The binding energy spectra and electron momentum density distributions for the valence orbitals of CF₂Br₂ have been obtained by using electron momentum spectroscopy (EMS) at an impact energy of 1200 eV plus binding energy. The measured electron momentum profiles are compared with Hartree–Fock (HF) and density functional theory (DFT) calculations with different-sized basis sets. In general, the DFT-B3LYP calculation using the large basis sets of 6-311++G** and aug-cc-pVTZ fairly describe the experimental results. Moreover, the controversial orderings of the outer valence orbitals have been reassigned. The pole strength of the main ionization transition from the inner valence orbital of 1b₂ is determined.     

CFCl3分子2e和4a1轨道的电子动量谱研究

由于工业的迅速发展 ,使得空气质量急剧下降 ,因此对影响大气的分子进行深入研究变得非常必要 .本实验室已经对影响环境的甲烷[1] 、丙烷[2 ] 、CO2 [3] 等分子进行了电子动量谱研究 ,为环保提供了有用的数据 .CFCl3作为工业广泛应用的气雾剂和制冷剂原料 ,它的大量使用导致了大气中臭氧的减少[4 ] .前人已用光电子谱学的方法[5- 8] 研究了CFCl3,我们又用电子动量谱的手段对CFCl3分子进行了进一步的研究 ,即从波函数的层次上详细了解CFCl3的电子结构 .(e ,2e)电子动量谱学在研究分子的电子结构方面有非常独特的优越性[9- 12 ] ,它可以…     

Experimental and calculated momentum densities for the complete valence orbitals of the antimicrobial agent diacetyl

The first electronic structural study of the complete valence shell binding energy spectra of the antimicrobial agent diacetyl, encompassing both the outer and inner valence regions, is reported. The binding energy spectra as well as the individual orbital momentum profiles have been measured by using a high resolution （e, 2e） electron momentum spectrometer （EMS） at an impact energy of 1200eV plus the binding energy, and using symmetric noncoplanar kinematics. The experimental orbital electron momentum profiles are compared with self-consistent field （SCF） theoretical profiles calculated using the Hartree-Fock approximation and Density Functional theory predictions in the target Kohn-Sham approximation which includes some treatment of correlation via the exchange and correlation potentials with a range of basis sets. The pole strengths of the main ionization peaks from the inner valence orbitals are estimated.     

(e, 2e) spectroscopy of N2—valence momentum distributions and configuration interaction

The noncoplanar symmetric (e, 2e) reaction has been applied to N₂ at 1200, 600 and 400 eV. Separation energy spectra are obtained in the valence region, the observed structure extending to above 60 eV. Electron momentum profiles are measured at a number of separation energies. They agree very well with the momentum distributions for valence orbitals given by SCF calculations. Considerable configuration interaction structure is observed, being primarily due to configuration interaction in the 2σ_g hole state. At 1200 eV the spectroscopic sum rule is satisfied within experimental error, confirming the validity of the analysis.     

(e,2e) Spectroscopy of ethane

The 400-eV and 1200-eV non-coplanar symmetric (e, 2e) reaction has been used to measure the momentum distributions of electrons in the individual valence orbitals of ethane as well as to measure the complete separation energy spectra in the valence region. The shapes and relative magnitudes of the momentum distributions agree well with those calculated using the plane wave off-shell impulse approximation and double zeta basis molecular orbital wave functions. The ground state of C₂H₆⁺ is shown to be 1e_g^?1, with the vertical ionization potential being 12.25 ± 0.1 eV. Considerable structure due to configuration interaction is observed in the separation energy region 29–55 eV. Much of this structure can be assigned to the 2a_1g orbital.     

Photoelectron spectra of F3SiC2H4Si(CH3)3 molecule using monochromatized synchrotron radiation

A variety of photoelectron spectra for gas phase F₃SiC₂H₄Si(CH₃)₃ molecule have been measured using monochromatized undulator radiation and a hemispherical electrostatic analyzer. Valence photoelectron spectrum shows many peaks for ionization from shallow and deep molecular orbitals in the binding energy region of 9–40 eV. A calculation of ionization energies using the outer valence Green's function method indicates energies in agreement with experimental results below 17.5 eV. Spectra for Si L-shell electron emission show chemical shifts of Si atoms induced from different chemical environments around two Si atoms and also exhibit spin–orbit splitting for 2p photoelectrons. Further photoelectron spectra for C K-shell and F K-shell are discussed in comparison with those of related molecules.     

Electron Momentum Spectroscopy of Ethanethiol Complete Valence Shell

利用(e,2e)电子动量谱学手段首次测量了乙硫醇分子全部价轨道的束缚能谱和电子动量分布. 谱仪采用非共面对称的运动学条件,入射电子能量为1.2 keV加束缚能. 实验结果与密度泛函和Hartree-Fock方法的理论计算结果基本相符. 在束缚能谱中,观察到了17.8 eV的可能的伴线,并用电子动量谱进行了研究和标识.