共查询到19条相似文献,搜索用时 390 毫秒
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本文采用谐振子模型,考虑Duschinsky效应,推得计算三维Franck-Condon因子的代数表示,且应用于研究硝酰自由基的光电子能谱的强度分布及振动结构。对于HNO((?)~3A″)-HNO~-((?)~2A″)光脱附过程,通过Franck-Condon因子计算,得到光电子能谱的谱线相对强度,理论上计算的光电子能谱与实验观测到的光电子能谱达到较好的一致;另外,在光谱模拟过程中,通过迭代Franck-Condon分析,拟合实验能谱得到阴离子HNO~-自由基(?)~2A″电子态的几何结构:键长R(NO)是0.1335±0.0005 nm,键角∠(HN())是106.3±0.5°. 相似文献
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本文采用谐振子模型, 考虑Duschinsky效应,推得计算三维Franck-Condon因子的代数表示,且应用于研究硝酰自由基的光电子能谱的强度分布及振动结构。 对于HNO( 3A″)– HNO‾( 2A″)光脱附过程,通过Franck-Condon 因子计算,得到光电子能谱的谱线相对强度,理论上计算的光电子能谱与实验观测到的光电子能谱达到较好的一致;另外,在光谱模拟过程中,通过迭代Franck-Condon分析,拟合实验能谱得到阴离子HNO‾自由基 2A″电子态的几何结构:键长R(NO)是0.1335 ± 0.0005 nm,键角(HNO)是106.3 ± 0.5o 。 相似文献
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用推广的U(2)代数模型,对正四面体分子的伸缩振动能谱进行了理 论研 究,该模型成功地应用到SnD4的最新观测到的高分辨能谱数据,所得计算值与实验值的标 准偏差是0.124 cm-1。 相似文献
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本文凭借多振动模混合下任意维Franck-Condon 重叠积分封闭表示,推导出三维三振动模Franck-Condon重叠积分的解析表示式;基于厄米多项式的级数形式,得到计算三维三振动模Franck-Condon 因子的一般代数表示式。 另外,应用Franck-Condon 因子的代数表示,研究甲醛光电子能谱的强度分布及振动结构。 对于H2CO+( 2A1)← H2CO( 1A1)离子化过程, 基于ab initio力常数及几何参数,计算Franck-Condon 因子,得到光电子能谱的谱线相对强度。 结果表明理论模拟得到的光电子能谱与实验上观测到的能谱达到较好的一致;基于光谱模拟使人们能够对实验谱给予合理解释以及对谱峰进行正确归属。 相似文献
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本文凭借多振动模混合下任意维Franck-Condon重叠积分封闭表示,推导出三维三振动模FranckCondon重叠积分的解析表示式;基于厄米多项式的级数形式,得到计算三维三振动模Franck-Condon因子的一般代数表示式.另外,应用Franck-Condon因子的代数表示,研究甲醛光电子能谱的强度分布及振动结构.对于H2CO+(珟Β2A1)←H2CO(珘X1A1)离子化过程,基于ab initio力常数及几何参数,计算FranckCondon因子,得到光电子能谱的谱线相对强度.结果表明理论模拟得到的光电子能谱与实验上观测到的能谱达到较好的一致;基于光谱模拟使人们能够对实验谱给予合理解释以及对谱峰进行正确归属. 相似文献
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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 相似文献
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在课题组前期建立的计算双核分子体系解析势能函数的代数能量自洽法(algebraic energy consistent method,AECM)的基础上,引入了经改进得到的精确研究双核分子完全振动能谱的变分代数法(variational algebraic method,VAM),获得了计算双核分子体系精确解析势能函数的变分代数能量自洽法(variational algebraic energy consistent method,VAECM)。基于有限的精确实验振动能谱数据,利用VAECM方法研究了Li_2分子1~3Δ_g,3~3Σ_g~+,1~3Σ_g~-和b~3Π_u等4个电子态的完全振动能谱和解析势能函数。获得了各电子态包含高阶的振动光谱常数、完全振动能谱、振动力常数fn和势能展开系数an,并通过可调变分参数λ最终确定了VAECM解析势能函数的具体表达形式。计算结果与其他方法的研究结果进行了比较,VAECM方法获得的振动能谱数据和势能解析表达形式能更好地描述这些电子态在渐近区和离解区的物理行为,消除了利用前期AECM方法研究这些电子态在离解区出现的非物理势垒现象。 相似文献
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S2O‾自由基光电子能谱的Franck-Condon分析 总被引:1,自引:1,他引:0
本文考虑多振动模混合和热带效应,凭借谐振子模型,推得计算两维-四振动模Franck-Condon重叠积分的解析表示,且应用于S2O‾ 自由基光电子能谱的理论研究。对于S2O( 1A′) – S2O‾( 2A″) 光脱附过程,结合分子轨道从头算和密度泛函理论,计算Franck-Condon因子,从而得到电子跃迁振动谱线的相对强度,理论上得到的光电子能谱与实验上观测到的能谱达到较好的一致;进一步在光谱模拟过程中,拟合实验能谱得到可靠的负离子自由基S2O‾电子态( 2A″)的几何结构参数:键长R(SS) = 2.008 +/-0.005Å 和 R(SO) = 1.519+/-0.005Å. 相似文献
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A U(2) algebraic model is introduced for the spectrum of a molecule XY4, where the interactions between the stretch and bend modes are
described by Td symmetric Fermi resonance terms. The presented algebraic model in a limit corresponds to another model in recent literature. The vibrational spectrum of methane
(CH4) measured recently with modern spectroscopy techniques
is employed to test those models. The obtained standard
deviation between the observed and the calculated vibrational energy
levels in the algebraic model is smaller than that
in the corresponding model. 相似文献
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The microwave spectrum of the energetically unfavored g'Gg conformer of ethylene glycol (CH(2)OH&bond;CH(2)OH) is reported. This spectrum is dominated by an interconversion geared-type large-amplitude motion during which each OH group in turn forms the intramolecular hydrogen bond. The microwave spectrum has been analyzed with the help of a Watson-type Hamiltonian plus a 1.4-GHz tunneling splitting. The rotational dependence of this tunneling splitting has been examined using an IAM approach and this yielded qualitative information on the tunneling path the molecule uses to interconvert between its two most stable conformers. Unexpectedly, but in agreement with ab initio calculations, when tunneling occurs between the energetically equivalent g'Gg and gGg' conformers, the OH groups are rotated stepwise through 240 degrees in the sense of a flip-flop rather than a concerted rotation and the molecule goes through the more stable g'Ga and aGg' forms. The electronic reasons for preferring a long rather than a short rotational path via a gGg form are discussed using calculated adiabatic vibrational modes. Copyright 2001 Academic Press. 相似文献
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我们提出一种描述XH3分子的伸缩和弯曲振动的U(2)代数哈米顿量,其中包括了伸缩和弯曲振动的费米共振耦合;用它来拟合CH3Cl分子的实验数据,结果表明有较少参数的代数模型算得的偏差比其它模型算得的偏差要小. 相似文献
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我们提出一种描述XH3分子的伸缩和弯曲振动的U(2)代数哈米顿量,其中包括了伸缩和弯曲振动的费米共振耦合,用它来拟合CH3Cl分子的实验数据,结果表明有较少参数的代数模型算得的偏差比其它模型算得的偏差要小. 相似文献
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Accurate studies on the full vibrational energy spectra and molecular dissociation energies for some electronic states of halogen molecule 下载免费PDF全文
This paper obtains accurate vibrational spectroscopic constants and full vibrational energy spectrum by the algebraic method (AM) for some electronic states of halogen diatomic molecules.Motivated by the recent success of obtaining the dissociation energies of Li 2 molecule by using a new analytical formula,it further extends the formula to study the dissociation energies of halogen diatomic molecules.The results show that the AM spectrum and the theoretical dissociation energies agree well with RKR data and experimental data respectively. 相似文献
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Selective control over the vibrational excitation and space quantization of the dissociation fragments by optimally designed
linearly polarized and shaped infrared (IR) laser pulses of the picosecond (ps) and subpicosecond duration is demonstrated
by means of quantum-dynamical simulations within the Schr?dinger wave-function formalism for a three-dimensional (3-D) model
of HONO2 in the ground electronic state, wherein the OH and the ON single-bond stretches are explicitly treated, together with the
bending angle between them, on the basis of the ab initio defined 3-D potential-energy surface and dipole function. The high-lying
zeroth-order vibrational states of the OH bond are prepared selectively both below and above the dissociation threshold of
the ON single bond, and demonstrate a quasi-periodic oscillatory behaviour, manifesting intramolecular vibrational energy
redistribution (IVR) on the picosecond timescale. Selective breakage of the ON single bond in HONO2 with more than 97% probability is demonstrated, along with control of the space quantization of the dissociation fragments:
the OH fragments rotating clockwise, OH(c), and anticlockwise, OH(a), are prepared selectively, with the OH(a)/OH(c) branching
ratio being as high as 10.975. The results obtained show that optimally designed strong and short IR-laser pulses can compete
against IVR and manipulate vibrational excitation and dissociation of polyatomic molecules.
Received: 3 November 1999 / Published online: 13 July 2000 相似文献
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The absorption spectrum of HDO has been recorded by intracavity laser absorption spectroscopy in the 16 540-17 055 cm(-1) spectral region corresponding to the 5nu(3) band centered at 16 920 cm(-1). The (0 0 5) vibrational state is found to be mostly isolated from the nearby rovibrational states. The corresponding rovibrational transitions were analyzed and fitted in the frame of the effective rotational Hamiltonian model in Pade-Borel approximants form. The spectroscopic parameters retrieved from the fitting reproduce 100 of the 109 determined energy levels with the root-mean-square deviation of 0.0072 cm(-1), close to the experimental accuracy. From the integrated relative intensities of a- and b-type transitions, the angle between the transition moment and the OH bond is estimated to be 46.4 degrees. This value is consistent with an increasing tilt of the transition dipole moment, away from the OH bond, when the OH stretching is excited. The evolution of the orientation of the transition dipole moment versus the vibrational excitation is then compared for the OH and OD overtone bands. Copyright 2000 Academic Press. 相似文献