H2SiCl2分子Si-H振动"基座"SiCl2的有效质量

用傅立叶变换光谱仪和激光腔内吸收光谱仪记录了H2 SiCl2 分子 2 0 0 0～ 90 0 0和 12 0 0 0～ 12 90 0cm-1的红外吸收光谱 .依据局域模理论的非谐性耦合非谐振子 (ACAO)模型 ,分析并拟合了Si-H的对称伸缩振动和反对称伸缩振动 ,得到描述Si-H伸缩振动的Morse离解能De、Morse振子参数α和键振子势能耦合系数frr′.分析中忽略了SiCl2 “基座”对Si-H伸缩振动的影响 ,拟合结果与实验值符合的很好 ,拟合方差小于 1cm-1,表明这一近似是可取的 .分析拟合结果表明 ,Si-H振动时“基座”SiCl2 的有效质量为 75 .     

CH2Cl2分子中CH的摇摆振动与伸缩和弯曲振动的耦合

用傅立叶变换光谱仪和光学长程装置,记录了CH_2Cl_2分子振动量子数v=1～4的红外吸收光谱(1200～12000 cm~(-1)),归属出CH的伸缩(v_1,v_6)振动和弯曲(v_2)振动和CH_2基团相对于CCl_2基团的摇摆振动(v_8)的泛频和合频能级共47个。考虑了摇摆振动与伸缩和弯曲振动的耦合,使用简正模模型对v_1,v_2,v_6和v_8这四种振动模式的泛频和合频能级进行了拟合,得到了非谐性常数和费米(Fermi)共振和达宁-丹尼生(Darling-Dennison)共振系数。结果表明,摇摆振动与伸缩振动之间的Fermi共振(k_(188)=-254.63 cm~(-1))大于弯曲振动与伸缩振动之间的Fermi共振(k_(122)=-54.87 cm~(-1))；伸缩振动之间的Darling-Dennison共振(k_(1166)=-215.28 cm~(-1))大于弯曲振动与摇摆振动之间的Darling-Dennison共振(k_(2288)=-5.72 cm~(-1))。用拟合得到的光谱参数计算出CH_2Cl_2分子的振动能级,与实验数据很好地符合。     

异丙醇的O-H伸缩振动泛频光谱和分子构像

使用高灵敏的光腔衰范光谱（Ｃａｕｉｔｙ Ｒｉｎｇ Ｄｏｗｎ Ｓｐｅｃｔｒｏｓｃｏｐｙ）技术测出了异丙醇的Ｏ－Ｈ伸缩ｖ＝４、５振动泛频光谱,每个技动能级都有三个吸收峰,被归属为分子构像的Ｏ－Ｈ伸缩泛叔汲收,给出了光腔衰范光谱的振动泛频吸收的振动谱强度公式,并求得分子不同构在不同振动能级的Ｏ－Ｈ伸缩局域模振子的机械频率（Ｘ１）、非谐性（Ｘ２）以及解离能（Ｄ）,用浓度泛函（ＤＦＴ）Ｂ３ＬＹＰ／６－３１＋     

氢同位素双原子分子的解析势能函数

研究从重水中分离出T2 .首先 ,根据光谱常数导出氢同位素双原子分子ExtendedRydberg的分析函数 ,基于同位素效应计算OT(X2 Пi)的光谱常数 ,有助导出三原子分子 ,如DTO的解析势能函数 .将这些ExtendedRyd berg解析势能函数用于氘交换分离氚的热力学与分子反应动力学研究 .此外 ,由同位素位移极值得到当振动量子数vmax≈ 11.5 ,振动能级间隔△Ev(H2 )≈△Ev(T2 ) ,若v △Ev(T2 )和v>vmax时 ,△Ev(H2 ) <△Ev(T2 ) .因而 ,温度较低时 ,平衡移向T2 ;温度较高时 ,平衡移向H2 .与文献结果相似 ,而导出方法不同     

Na2分子部分电子态的完全振动能谱和离解能的精确研究

对于大多数双原子分子的电子态，用现代实验方法或精确的量子理论方法往往可以获得含m个振动能级的能谱子集合［Ev］，而不易得到包含最高振动能级在内的所有高振动量子态能级的完全振动能谱{Ev}.鉴于Na2分子电子态的振动能谱和分子离解能De在实际研究和应用中的重要性，使用基于微扰理论的代数方法（AM），获得了Na2分子一些电子态的振动光谱常数和完全振动能谱；使用基于AM的代数能量方法（AEM）获得了这些电子态的正确离解能.研究结果表明：AM方法能从少数精确的实验能级获得精确的分子振动光谱常数集合和正确的完全振动能谱{Ev}，AEM方法获得的分子离解能比由文献发表的振动光谱常数计算得到的近似离解能值更准确，对于难以获得分子离解能的那些电子激发态，AEM方法能给出合理的离解能数据. 关键词： Na2分子 代数方法 振动能级 离解能 电子激发态     

高激发振动态氰化氢分子的解离研究

运用李代数陪集空间方法，结合莫尔斯（Morse）振子的解离特点研究了具有多重共振的高 激发振动态氰化氢（HCN）分子的解离.结果表明，分子振动模之间的共振（主要是体系的高 次共振）作用，有助于化学键的解离，共振的作用导致H—C键解离能量的降低. 关键词： 高激发振动态 共振 解离     

CH3D分子3V2泛频态高分辨红外光谱的振动分析

用最小二乘法拟合ＣＨ３Ｄ分子６４２８ｃｍ＾－１附近振动带的１３８个能级，１０个振动常数。振动分析阐明带为ＣＨ３分子Ｃ－Ｄ对称伸缩振动３Ｖ２态，并与局域模振动理论计算值进行了比较。     

PH3分子高能振动谱的非线性模型计算

利用非线性量子理论中的一个三参数模型－量子化的离散自陷方程－对ＰＨ３分子处于高能振动态下的ＰＨ键的伸缩振动能谱进行了理论计算（１≤ｎ≤７，ｎ为ＰＨ３分子的总振动量子数）获得了与实测谱数据符合较好的结果（其均方根ＲＭＳ偏差约为３．８８ｃｍ＾－１）预测了一些泛频和组频谱带的中心位置，并将振动能级按地称性进行了归类，在计算过程中，模型Ｈａｍｉｌｔｏｎ算符Ｈ中所包含的描述ＰＨ键非谐振动的参数λ和描述ＰＨ键     

Na2分子部分电子态的完全振动能谱和离解能的精确研究

对于大多数双原子分子的电子态,用现代实验方法或精确的量子理论方法往往可以获得含m个振动能级的能谱子集合[Ev],而不易得到包含最高振动能级在内的所有高振动量子态能级的完全振动能谱{Ev}.鉴于Na2分子电子态的振动能谱和分子离解能De在实际研究和应用中的重要性,使用基于微扰理论的代数方法(AM),获得了Na2分子一些电子态的振动光谱常数和完全振动能谱;使用基于AM的代数能量方法(AEM)获得了这些电子态的正确离解能.研究结果表明:AM方法能从少数精确的实验能级获得精确的分子振动光谱常数集合和正确的完全振动能谱{Ev},AEM方法获得的分子离解能比由文献发表的振动光谱常数计算得到的近似离解能值更准确,对于难以获得分子离解能的那些电子激发态,AEM方法能给出合理的离解能数据.     

HXD中XH拉伸振动的振动跃迁偶极矩方向的理论研究

本文利用局域模研究了“重轻”体系简单分子XH伸缩振动的实验振动光谱. 键偶极方法进一步为实验光谱分析提供了帮助(假设XH伸缩振动的跃迁偶极矩沿着XH键方向排列). 通过局域模和多维简正模对HOD，HND^-，HCD，HSD，HPD^-和HSiD的XH伸缩振动的理论计算， XH伸缩振动的局部1D图片可以用于分析跃迁偶极矩倾斜角度. 在HOD分子中，OH伸缩振动的跃迁偶极矩远离OH键并且向远离OD键的方向倾斜；在HSD，HND^-，HPD^-，HCD和HSiD分子中的XH伸缩振动远离OH键，但朝向OD键，表明键偶极近似法不能很好地适用于“重轻体系”分子，重原子X可以影响跃迁偶极矩方向. 利用分子中原子理论分析了偶极矩的变化.     

The infrared spectrum of the ν1 and ν4 bands of 28SiH3D

The spectrum of the ν₁ and ν₄ SiH stretching bands of ²⁸SiH₃D have been recorded and analyzed. The degenerate stretching mode is at 2188.504 cm^?1, only 1.103 cm^?1 above the symmetric stretching mode. Several accidental and essential resonances affect these bands but all have been successfully analyzed by diagnolization of the secular determinant complete through the second order of the transformed Hamiltonian. One accidental resonance leads to a number of forbidden transitions through which a value of the rotational constant A₀ has been obtained.     

Fermi resonance and vibrational analysis of SiH2 ( ) based on the LIF excitation spectra of the transitions

SiH₂ radicals were generated in a free jet by the 193 nm photolysis of phenylsilane and the LIF excitation spectra of vibrationally excited SiH₂ ( ) were observed. The spectra were utilized to determine the vibrational frequencies and anharmonic constants for the symmetric stretching and the bending vibrations. Analysis of the Fermi resonance between the (100) and (020) levels gave interaction energy of 12.4 cm⁻¹.     

用耦合簇理论及相关一致五重基研究SiH$lt;sub$gt;2$lt;/sub$gt;($lt;i$gt;X$lt;/i$gt;$lt;sup$gt;1$lt;/sup$gt;$lt;i$gt;A$lt;/i$gt;$lt;sub$gt;1$lt;/sub$gt;)自由基的解析势能函数

运用单双迭代三重激发耦合簇理论和相关一致五重基对SiH₂的基态结构进行了优化, 并在优化结构的基础上进行了离解能和振动频率的计算. 结果表明: SiH₂的基态为C_2v结构, 平衡核间距R_Si—H= 0.15163 nm, H—Si—H键的键角α=92.363°, 离解能D_e（HSi—H）=3.2735 eV, 频率ν₁（a₁）=1020.0095 cm^-1, ν₂（a₁）=2074.8742 cm^-1, ν₃（a₁）=2076.4762 cm^-1. 这些结果与实验值均较为相符. 对H₂的基态使用优选出的cc-pV6Z基组、对SiH的基态使用优选出的aug-cc-pV5Z基组进行几何构型与谐振频率的计算并进行单点能扫描, 且将扫描结果拟合成了解析的Murrell-Sorbie函数. 与实验结果及其他理论计算结果的比较表明, 本文关于SiH自由基光谱常数（D_e,R_e, ω_e, B_e, α_e和ω_eχ_e）的计算结果达到了很高的精度. 采用多体项展式理论导出了SiH₂（C_2v, X¹A₁）自由基的解析势能函数, 其等值势能图准确再现了它的离解能和平衡结构特征. 同时还给出了SiH₂（C_2v, X¹A₁）自由基对称伸缩振动等值势能图中存在的两个对称鞍点, 对应于SiH+H→SiH₂反应, 势垒高度为0.5084 eV. 关键词： 2')" href="#">SiH₂ Murrell-Sorbie函数 多体项展式理论 解析势能函数     

Dynamically based fitting law for cross-sections of vibrational energy transfer

A three-dimensional semiclassical analytical model for cross-sections of vibrational energy transfer in collisions between an atom and a diatomic molecule has been developed. The model is based on the Bessel uniform approximation for transition probabilities valid for highly excited states of a molecule represented by the Morse oscillator. Three fitting parameters of the model are expressed in terms of the features characterizing the anisotropic intermolecular potential. The accuracy and validity of this law are tested by comparison with large Δn transitions and isotope effects in the crossed beam inelastic scattering of I₂ from He, H₂ and D₂.     

Photophysical studies of uranyl complexes 5. Luminescence spectrum of K4UO2(CO3)3

The photoluminescence of K₄UO₂(CO₃)₃ has been studied under conditions of high resolution at cryogenic temperatures. The origin corresponding to the pure electronic transition was located at 4774 Å (20945 cm^-1), and it was found that the totally symmetric uranyl stretching mode was coupled to this transition. A progression of four band systems thus resulted, and from an examination of the energies of corresponding peaks in each system, a value of 813 cm^-1 for the U-O stretching mode was determined. Two lattice modes (34 and 80 cm^-1) and two molecular vibrational modes (205 and 276 cm^-1) were also found to couple with the pure electronic transition, thus yielding approximately 15 major peaks in each band system. The 205 cm^-1 vibration corresponded to a CO^2-₃ vibration, while the 276 cm^-1 vibration was a UO²⁺₂ deformation. The low values obtained for the force constant and totally symmetric stretching frequency of the U-O bond suggested that in UO₂(CO)^4-₃, the uranium atom is bound in a complex species that may be considered as an intermediate between that of a uranyl (UO²⁺₂) and a uranate (UO^10-₈) ion.     

Ring-puckering combination band spectra of 1,3-disilacyclobutane in the SiH2 stretching region

Three sets of sum bands and two sets of difference bands arising from the combination of the ring-puckering vibration with SiH₂ stretching modes have been observed between 2060 and 2260 cm^?1 in the infrared spectrum of 1,3-disilacyclobutane. An unusual feature of the spectrum is that there is little correlation in intensity between corresponding sum and difference bands. An additional sum band and a difference band were also observed in the Raman spectrum. The spectra confirm the low-frequency ring-puckering assignment and verify the position of the weak 2–3 transition near 31 cm^?1. The puckering levels in the excited states of the SiH₂ stretching modes are virtually unshifted relative to the ground state demonstrating that negligible coupling exists between these vibrations. In addition, sum and combination bands have been observed off an SiD₂ stretching mode for 1,3-disilacyclobutane-1,1,3,3-d₄.     

Microwave spectrum of silyl fluoride: Coriolis resonance between ν2 and ν5 states

The J = 1 ← 0 and J = 2 ← 1 microwave rotational transitions of SiH₃F and SiD₃F have been measured for the ground and the v₂ = 1, v₃ = 1, v₅ = 1, and v₆ = 1 vibrational states, for which the various rotational and vibration-rotation interaction constants have been obtained. Both molecules show an X-Y Coriolis resonance between the ν₂ and ν₅ vibrational states, whose separation are 29 and 8 cm^?1, respectively. In the case of SiD₃F the resonance is very strong and an exact numerical diagonalization of the energy matrix was employed.     

AsO+同位素离子X2∑+和A2∏电子态的多参考组态相互作用方法研究

采用包含Davidson修正多参考组态相互作用(MRCI)方法结合价态范围内的最大相关一致基As/aug-cc-pV5Z和O/aug-cc-pV6Z, 计算了AsO⁺ (X²∑⁺)和AsO⁺(A²∏)的势能曲线. 利用AsO⁺离子的势能曲线在同位素质量修正的基础上, 拟合出了同位素离子⁷⁵As¹⁶O⁺和⁷⁵As¹⁸O⁺的两个电子态光谱常数. 对于X²∑⁺态的主要同位素离子⁷⁵As¹⁶O⁺, 其光谱常数R_e, ω_e, ω_ex_e, B_e和α_e分别为 0.15770 nm, 1091.07 cm^-1, 5.02017 cm^-1, 0.514826 cm^-1和0.003123 cm^-1; 对于A²∏态的主要同位素离子⁷⁵As¹⁶O⁺, 其T_e, R_e, ω_e, ω_ex_e, B_e和α_e分别为5.248 eV, 0.16982 nm, 776.848 cm^-1, 6.71941 cm^-1, 0.443385 cm^-1和0.003948 cm^-1. 这些数据与已有的实验结果均符合很好. 通过求解核运动的径向薛定谔方程, 找到了J=0时AsO⁺(X²∑⁺)和AsO⁺(A²∏)的前20个振动态. 对于每一振动态, 还分别计算了它的振动能级、转动惯量及离心畸变常数, 并进行了同位素质量修正, 得到各同位素离子的分子常数. 这些结果与已有的实验值非常一致. 本文对于同位素离子⁷⁵As¹⁶O⁺(X¹∑⁺), ⁷⁵As¹⁸O⁺(X¹∑⁺), ⁷⁵As¹⁶O⁺(A¹∏)和⁷⁵As¹⁶O⁺(A¹∏)的光谱常数和分子常数属首次报导.     

Simultaneous analysis of the ν1, ν4, 2ν2, ν2 + ν5, and 2ν5 infrared bands of 12CH3F

The Fourier-transform spectrum of CH₃F from 2800 to 3100 cm^?1, obtained by Guelachvili in Orsay at a resolution of about 0.003 cm^?1, was analyzed. The effective Hamiltonian used contained all symmetry allowed interactions up to second order in the Amat-Nielsen classification, together with selected third-order terms, amongst the set of nine vibrational basis functions represented by the states ν₁(A₁), ν₄(E), 2ν₂(A₁), ν₂ + ν₅(E), 2ν₅⁰(A₁), and 2ν₅^±2(E). A number of strong Fermi and Coriolis resonances are involved. The vibrational Hamiltonian matrix was not factorized beyond the requirements of symmetry. A total of 59 molecular parameters were refined in a simultaneous least-squares analysis to over 1500 upper-state energy levels for J ≤ 20 with a standard deviation of 0.013 cm^?1. Although the standard deviation remains an order of magnitude greater than the precision of the measurements, this work breaks new ground in the simultaneous analysis of interacting symmetric top vibrational levels, in terms of the number of interacting vibrational states and the number of parameters in the Hamiltonian.     

Rotational dependence of Franck-Condon factors for OH+, NH+, SiH,MgH+, SiH+, and NO+

The rotational dependence of Franck-Condon factors has been calculated for OH⁺, NH⁺, SiH, MgH⁺, SiH⁺, and NO⁺ using the rotating Morse oscillator model. A rotational dependence is noticed in the electronic bands of each of these molecular species; this dependence may make a significant contribution in the determination of rotational temperatures, abundances and opacity distribution functions.