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1.
Introduction Scattering resonance states in chemical reactionsattract much interest of both theorists and experimental-ists because the rate of a chemical reaction, state distri-bution and space distribution of the products are con-trolled by those states[1]. Scattering resonance states,also called quasi-bound states, are formed in theprocesses of energy transitions, such as collision andray radiation processes. Those states are very closelyrelated to the structure and spectroscopy of the tran…  相似文献   

2.
The partial potential energy surface of the I + HI →IH + I reaction involving the translational and vibrational motions has been constructed at the QCISD( T )//MP4SDQ level with the pseudo potential method that is helpful to interpreting the scattering resonance states. The lifetimes of the scattering resonance states in the title reaction obtained from the partial potential energy surface are about 90-120 fs, which agrees with the result of high-resolved threshold photodetachment spectroscopy of anion IHI^- measured by Neumark.  相似文献   

3.
在 QCISD ( T) / / MP2水平下 ,分别采用 6-3 1 1 ++G* * 基组和 SDD基组对重 -轻 -重反应 I+HI(ν=0 )→ IH(ν′=0 ) +I中的 H和 I的偏分势能面进行了 ab initio计算 ,指认出在 0~ 0 .5 8e V碰撞能范围内所产生的 6个散射共振态为 Feshbach共振 ,并与文献报道的量子散射理论计算与高分辨阈值光分离光谱实验结果进行了比较 .  相似文献   

4.
在QCISD(T)//MP2水平下,分别采用6-311++G**基组和SDD基组对重-轻-重反应I+HI(υ=0)→IH(υ′  相似文献   

5.
The partial potential energy surface(PPES) of Br+HBr(v=0)→BrH(v'=0)+Br was designed by coupling the vibration energy and the minimum energy of the corresponding reaction path, Vmep. All the calculations were performed at the theoritical level of QCISD(T)/6-311++G**//MP2/6-31 1++G**. Based on the analysis of PPES, the dynamic "Eyring Lake" mechanism gave birth to the scattering resonance state. The resonance energy was also obtained via PPES. Then a lifetime matrix of the resonance state was established by solving the translational wave-function via the numerical propagation method. Then the reaction resonance lifetime was calculated to be 125 fs. It is in good agreement with the experimental result.  相似文献   

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Many reactions with fluorine atoms have the important applications in the areas of theatmosphere and the chemical lasers, such as the reaction of fluorine atoms with methane. F( 2 P) CH 4 (X1A1)→HF(X1 Σ ) CH 3 (X 2 A′′2) ?H0300k=-32.3 kcal mol ?1 It…  相似文献   

8.
本文基于振动绝热性分析,用量子散射理论研究I+HI′(v)→IH(V′)+I′反应几率的振荡行为,其中双原子间相互作用势和振动本征态是Morse振子的严格解.在计算反应几率时采用分布高斯基(Distributed Gaussian Basis Sets;DGBS)展开方法,既保持了反应几率的解析表达式,又有效地简化了计算.计算结果明显地揭示了反应几率在低碰能区域的振荡行为.对反应机理也作了探讨.  相似文献   

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10.
蔡政亭  赵显  邓从豪 《化学学报》1995,53(11):1054-1059
本文基于振动绝热性分析, 用量子散射理论研究I+HI'(v)→IH(v')+I'反应几率的振荡行为, 其中双原子间相互作用势的振动本征态是Morse振子的严格解。在计算反应几率时采用分布高斯基(Distributed Gaussian Basis Sets; DGBS)展于方法, 既保持了反应几率的解析表达式, 又有效地简化了计算。计算结果明显地揭示了反应几率在低碰能区域的振荡行为。对反应机理也作了探讨。  相似文献   

11.
在QCISD(T)//MP2水平下,分别采用6-311 G基组和SDD基组对重-轻-重反应I HI(p=0)→IH(√=0) I中的H和I的偏分势能面进行了abinitio计算.指认出在0~0.58eV碰撞能范围内所产生的6个散射共振态为Feshbach共振,并与文献报道的量子散射理论计算与高分辨阈值光分离光谱实验结果进行了比较.  相似文献   

12.
The quasi-classical trajectory calculations O++DH (v=0, j=0)→OD++H reactions on the RODRIGO potential energy surface have been carried out to study the isotope effect onstereo-dynamics at the collision energies of 1.0, 1.5, 2.0, and 2.5 eV. The distributions of dihedral angle P(φr) and the distributions of P(θr) are discussed. Furthermore, the angular distributions of the product rotational vectors in the form of polar plot in θr and φr are calculated. The differential cross section shows interesting phenomenon that the reaction is dominated by the direct reaction mechanism. Reaction probability and reaction cross section are also calculated. The calculations indicate that the stereo-dynamics properties of the title reactions are sensitive to the collision energy.  相似文献   

13.
<正>Quasi-classical trajectory(QCT) calculations have been carried out to study the generalized polarization dependent differentialcross sections(PDDCSs) for the reactions H + LiH~+(v = 0,j = 0)→H_2 + Li~+ and H~+ + LiH(v = 0,j = 0)→H_2~+ + Li occurring onthe two lowest-lying electronic states of the LiH_2~+ system,using the ab initio potential energy surfaces(PESs) of Martinazzo et al.[3].Four PDDCSs,i.e.,(2π/σ)(dσ_(00)/dω_t),(2π/σ)(dσ_(20)/dω_t),(2π/σ)(dσ_(22+)/dω_t),(2π/σ)(dσ_(21-)/dω_t) have been discussed in detail.  相似文献   

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Thepastfewyearshavewitnessedanincreasinglevelofinterestinthestudyofchemicalreactiondyntalcsboththeoreticallyandexperimentallyt'J.EsPeciallythemolecularbeamexperimenthasrnaderemarkableprOgressandhasstimulatedtheoreticalstudies.Itis,h0wever,stillaverydiffcultproblemtocalculatereactioncrosssectionsandrateconstantsacctiratelyeveninthecaseofD+H2(j,,vi=O)-DH(jf,vf=O)+H,whichrepresentsthesdriplestbutmostfundamenta1reactionsystem.Someattemptshavebeenmadetompoutveryaccuratequantummechanica-lcalcula…  相似文献   

16.
The quasi-classical trajectory calculation for the reaction O(1D)+HD is carried out based on the Dobbyn and Knowles potential energy surface. In this work, the reaction cross section and product branching ratio are obtained. The product branching ratio OD/OH was discussed. The calculated results show that the cross-section decreases thoroughly with the increasing of the collision energy from 4.6 kJ/mol to 46.0 kJ/mol. The average branching ratio decrease with the increase of rotational quantum number of reactant HD.  相似文献   

17.
基于Aguado等人拟合的APW势能面(PES),运用准经典轨线(QCT)方法,对反应Li+HF(v=0,j=0)→LiF+H的动力学性质进行了计算.主要研究了不同碰撞能条件下的反应截面、转动取向、产物散射角分布和竞争反应模式等.结果表明,该反应存在直接提取型和间接插入型两种反应模式,在低能量下反应以间接插入反应模式为主,能量大于200 meV时则以直接提取反应为主.  相似文献   

18.
Summary A quantum mechanical calculation of cross sections for the reaction F+H2(v=0,j=0) FH(vj)+H has been performed on the T5A semiempirical potential surface using hyperspherical coordinates. State-to-state integral and differential cross sections converge rapidly with the number of components of the total angular momentum projection onto the axis of least inertia. Thev=3 differential cross section has a forward peak whose magnitude increases with energy whereas thev=2 differential cross section has a backward maximum, in qualitative agreement with cross-beam experiments. Thev=2 andv=3 rotational distributions are in rather good agreement with experiment, but not the vibrational branching ratios.  相似文献   

19.
A new potential energy surface is presented for the triplet state 3A' of the chemical reaction S(3P)+H2 from a set of accurate ab initio data. The single point energies are computed using highly correlated complete active space self-consistent-field and multi-reference config-uration interaction wave functions with a basis set of aug-cc-pV5Z. We have fitted the full set of energy values using many-body expansion method with an Aguado-Paniagua function. Based on the new potential energy surface, we carry out the time-dependent wave packet scattering calculations over the collision energy range of 0.8~2.2 eV. Both the centrifugal-sudden approximation and Coriolis Coupling cross sections are obtained. In addition, the total reaction probabilities are calculated for the reactant H2 initially in the vibrational states v=0~3 (j=0). It is found that initial vibrational excitation enhances the title reaction.  相似文献   

20.
The product alignment and orientation of the title reaction on the ground potential energy surface of 1 (2)A' have been studied using the quasi-classical trajectory method. The calculations were carried out for case (a) at collision energies of 0.5-20 kcal mol(-1) with the initially rovibrational state of the reagent FCl molecule being at the v = 0 and j = 0 level to especially reveal in detail the dependence of the product integral cross section on collision energy. Further calculations at the collision energy of 15 kcal mol(-1) for case (b) at v = 0-5, and j = 0, and (c) at v = 0, and j = 3, 6, 9 initial states were carried out to reveal the effect of initially vibrational and rotational excitations on stereodynamics, respectively. Possessing final relative velocity k' (defined as a vector in the xz-plane), product alignment perpendicular to the reagent relative velocity vector k (defined as z- or parallel to the z-axis), for case (a) is found to be weaker at all collision energies, for case (b) is found to be vibrationally enhanced by the reactant molecule FCl, but for case (c), rather insensitive to initially rotational excitation. The rotational vector of product molecular orientation pointing to either negative or positive direction of the y-axis in the center of mass frame, e.g. origin of the coordinate system, is enhanced by collision energies regarding to 0.5-20 kcal mol(-1), while it becomes weaker at higher vibrational (v = 0-5) or rotational (j = 0, 3, 6, 9) excitation levels. Effects of collision energies and of rotational excitation at these collision energies, with 15 kcal mol(-1) as an example on the calculated PDDCSs are also shown and discussed. Detailed plots P(φ(r)) in the range of 0 ≤φ(r)≤ 360(o), and P(θ(r), φ(r)) in the ranges of 0 ≤θ(r)≤ 180° and 0 ≤φ(r)≤ 360° at collision energies 0.5-20 kcal mol(-1) have been presented. Overall, results of PDDCSs of the product alignment and product orientation at these collision energies in the title reaction are not very strongly distinguishable.  相似文献   

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