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1.
Quasi-classical trajectory(QCT) studies on the stereodynamics of H + Br O → O + HBr reaction have been performed on the X1A′state of ab initio potential energy surface by Peterson [Peterson K A 2000 J. Chem. Phys. 113 4598] in a collision energy range from 0 kcal/mol to 6 kcal/mol. Two of the polarization-dependent generalized differential cross sections(PDDCSs),(2π /σ)( dσ00/ dωt)(PDDCS00) and(2π /σ)( dσ20/ dωt)(PDDCS20) are considered. The rotational polarizations of these products show sensitive behaviors to the calculated collision energy range. Furthermore, in order to gain more knowledge about vector correlations, the product angular distribution, P(θr), and the dihedral angle, P(φr),are calculated, and the results indicate that both the rotational alignment and orientation of the product are enhanced as collision energy increases.  相似文献   

2.
We investigate the influence of reagent vibration on the stereodynamics of the title reaction by the quasi-classical trajectory on the Aguado-Paniagua2-potential energy surface developed by Aguado et al.(J.Chem.Phys.1997 106 1013).The cross sections and reaction probability as functions of the reagent vibration are calculated in the centre-ofmass frame.The product angular distributions of p(θr),p(φr),and p(θr,φr),which reflect the vector correlation,are also presented and discussed.The results indicate that the vector properties are sensitively affected by the vibrational excitation.  相似文献   

3.
尹淑慧  邹静涵  郭明星  李磊  许雪松  高宏  车丽 《中国物理 B》2013,22(2):28201-028201
The stereodynamics of the abstraction reaction H + NeH+(v = 1-3,j = 1,3,5) → H2+ + Ne is studied theoretically with a quasi-classical trajectory method on a new ab initio potential energy surface [ S J,Zhang P Y,Han K L and He G Z 2012 J.Chem.Phys.132 014303].The effects of vibrational and rotational excitation of reagent molecules on the polarization of the product are investigated.The reaction cross sections,the distributions of P(θr),P(φr),and polarizationdependent differential cross sections(PDDCSs) are calculated.The obtained cross sections indicate that the title reaction is a typical barrierless atom(ion)-ion(molecule) reaction.The initial vibrational excitation and rotational excitation of reagent molecules have distinctly different influences on stereodynamics of the title reaction,and the possible reasons for the differences are presented.  相似文献   

4.
Vector correlations of the reaction N(2D)+ H2(X1Σ+g) → NH(a1?)+ H(2S) are studied based on a recent DMBESEC PES for the first excited state of NH2[J. Phys. Chem. A 114 9644(2010)] by using a quasi-classical trajectory method.The effects of collision energy and the reagent initial vibrational excitation on cross section and product polarization are investigated for v = 0–5 and j = 0 states in a wide collision energy range(10–50 kcal/mol). The integral cross section could be increased by H2 vibration excitation remarkably based on the DMBE-SEC PES. The different phenomena of differential cross sections with different collision energies and reagent vibration excitations are explained. Particularly,the NH molecules are scattered mainly in the backward hemisphere at low vibration quantum number and evolve from backward to forward direction with increasing vibration quantum number, which could be explained by the fact that the vibrational excitation enlarges the H–H distance in the entrance channel, thus enhancing the probability of collision between N atom and H atom. A further study on product polarization demonstrates that the collision energy and vibrational excitation of the reagent remarkably influence the distributions of P(θr), P(φr), and P(θr, φr).  相似文献   

5.
The vector correlations in the reaction F+H2 (v =0-3, j =0-3)→ HF(v', j')+H are investigated using the quasi- classical trajectory method on the Stark-Werner potential energy surface at a collision energy of 1.0eV. The potential distribution P(θr) to angles between k and j', the distribution P(Фr) to dihedral angles, denoting k - k' - j' correlation and the polarization-dependent generalized differential cross sections, are calculated. The effect of reagent vibrational and rotational excitation on the F+H2 reaction is discussed in detail The results suggest that the different vibrational and rotational quantum states of H2 have different influences on the product polarization.  相似文献   

6.
朱通  扈国栋  陈建中  刘新国  张庆刚 《中国物理 B》2010,19(8):83402-083402
<正>The vector correlation between products and reagents for reaction O(~3P)+HCl→OH+Cl is studied using a quasiclassical trajectory(QCT) method on the benchmark potential energy surface of the ground ~3A" state[Ramachandran and Peterson,J.Chem.Phys.119(2003)9550].The generalised differential cross section(2π/σ)(dσ_(00)/dω_t) is presented in the centre of mass frame.The distribution of dihedral angles,P(φr),and the distribution of angles between k and j', P(θ_r),are calculated.The influence of the collision energy and the influence of the reagent rotation and vibration on the product polarization are studied in the present work.The calculated results indicate that the rotational polarization of the product molecule is almost independent of collision energy but sensitive to the reagent rotation and vibration.  相似文献   

7.
In this paper, the stereodynamics of Li + DF → Li F + D reaction is investigated by the quasi-classical trajectory(QCT)method on the ^2A' potential energy surface(PES) at a relatively low collision energy of 8.76 kcal/mol. The scalar properties of the title reaction such as reaction probability and cross section are studied with vibrational quantum number of v = 1–6. The product angular distributions P(θr) and P(φr) are presented in the same vibrational level range. Moreover, two polarization-dependent generalized differential cross sections(PDDCSs), i.e., the PDDCS00 and PDDCS22+are calculated as well. These stereodynamical results demonstrate sensitive behaviors to the vibrational quantum numbers.  相似文献   

8.
岳现房 《中国物理 B》2012,21(7):73401-073401
Stereodynamics for the reaction H+LiF(v=0, j=0) → HF+Li and its isotopic variants on the ground-state (1 2 A′) potential energy surface (PES) are studied by employing the quasi-classical trajectory (QCT) method. At a collision energy of 1.0 eV, product rotational angular momentum distributions P (θr), P (φr), and P (θr ,φr), are calculated in the center-of-mass (CM) frame. The results demonstrate that the product rotational angular momentum j′ is not only aligned along the direction perpendicular to the reagent relative velocity vector k, but also oriented along the negative y axis. The four generalized polarization-dependent differential cross sections (PDDCSs) are also computed. The PDDCS 00 distribution shows a preferential forward scattering for the product angular distribution in each of the three isotopic reactions, which indicates that the title collision reaction is a direct reaction mechanism. The isotope effect on the stereodynamics is revealed and discussed in detail.  相似文献   

9.
A quasi-classical trajectory(QCT) calculation is used to investigate the vector and scalar properties of the D + Br O → DBr + O reaction based on an ab initio potential energy surface(X1A state) with collision energy ranging from 0.1 kcal/mol to 6 kcal/mol. The reaction probability, the cross section, and the rate constant are studied. The probability and the cross section show decreasing behaviors as the collision energy increases. The distribution of the rate constant indicates that the reaction favorably occurs in a relatively low-temperature region(T 100 K). Meanwhile, three product angular distributions P(θr), P(φr), and P(θr, φr) are presented, which reflect the positive effect on the rotational angular momentum j' polarization of the DBr product molecule. In addition, two of the polarization-dependent generalized differential cross sections(PDDCSs), PDDCS00 and PDDCS20, are computed as well. Our results demonstrate that both vector and scalar properties have strong energy dependence.  相似文献   

10.
Quasiclassical trajectory (QCT) calculations are first carried out to study the stereodynamics of the S (3p) + H2 → SH + H reaction based on the ab initio 13Atr potential energy surface (PES) (Lii etal. 2012 J. Chem. Phys. 136 094308). The QCT-calculated reaction probabilities and cross sections for the S + H2 (v = 0, j = 0) reaction are in good agreement with the previous quantum mechanics (QM) results. The vector properties including the alignment, orientation, and polarization- dependent differential cross sections (PDDCSs) of the product SH are presented at a collision energy of 1.8 eV. The effects of the vibrational and rotational excitations of reagent on the stereodynamics are also investigated and discussed in the present work. The calculated QCT results indicate that the vibrational and rotational excitations of reagent play an important role in determining the stereodynamic properties of the title reaction.  相似文献   

11.
The vector correlations between products and reagents for the reactions Ne+H2+, Ne+D2+, and Ne+T2+ are calculated by means of the quasi-classical trajectory method on a new potential energy surface constructed by Lfi et al, [J. Chem. Phys. 2010 132, 014303]. The polarization-dependent differential cross-sections (27π/σ)(dσ00/dωt), (2π/σ)(dσ20/dwt), (27π/σ)(dσ22+/dwt), and (2π/σ)(dσ21-/dwt), and the distributions of P(θr), P(φ), and P(θr, Cr) are calculated. The isotopic effect, which is associated with the difference in mass factor among the three reactions, is revealed.  相似文献   

12.
岳现房 《中国物理 B》2013,(11):275-281
A state-to-state dynamics analysis for the Li+HF(v=0,j=0)→LiF(v',j')+H collision reaction has been performed through quasiclassical trajectory(QCT)calculations.It is found that the differential cross section(DCS)of the LiF products from the title reaction is preferentially backward scattering for v=0,yet forward scattering for v=1 and 2.For v=3,the DCS exhibits forward,backward,and sideways scatterings.The variation of the internuclear distances and angles along the propagation time reveals that more than 99.08%of reaction trajectories undergo the direct reaction mechanism.The values of the polarization parameters a{1}1and a{2}0demonstrate that the product rotational angular moment j' is not only aligned perpendicular to the reagent relative velocity vector,but also oriented along the negative y axis.These product polarization results agree well with the recent quantum mechanical studies.The mechanism of these results was proposed and discussed in detail.  相似文献   

13.
<正>The quasi-classical trajectory(QCT) method is used to calculate the stereo-dynamics of the exchange reaction H_a+LiH_b→LiH_a+H_b and its isotopic variants based on an accurate potential energy surface reported by Prudente et al.[Prudente F V,Marques J M C and Maniero A M 2009 Chem.Phys.Lett.474 18].The reactive probability of the title reaction is computed.The vector correlations and four polarization-dependent generalized differential cross sections(PDDCSs) at different collision energies are presented.The influences of the collision energy and the reagent rotation on the product polarization are studied in the present work.The results indicate that the product rotational angular momentum j’ is not only aligned,but also oriented along the direction perpendicular to the scattering plane. The product polarization distributions of the title reaction and its isotopic variants exhibit distinct differences which may arise from different mass combinations.  相似文献   

14.
The isotope effect on the stereodynamic properties in the title reaction is investigated by a quasi-classical trajectory (QCT) method on the 11At potential energy surface at a collision energy of 23.06 kcal/mol. The angular distributions P(φr ), P(θr), P(θr, φr), and the polarization-dependent generalized differential cross sections are calculated, which demonstrate the observable influences on the rotational polarization of the product by the isotopic substitution of H with D.  相似文献   

15.
Quasi-classical trajectory calculations of the title reactions H + C1F (v = 0-5, j = 0, 3,6, 9) -+ HCl + F and H + C1F (v = 0-5, j =0, 3, 6, 9) → HF + C1 at Erel = 0.5 kcal/mol-20 kcal/mol on ground potential energy surface DHTSN of 1 2AI [M. E Deskevich, M. Y. Hayes, K. Takahashi, R. T. Skodje and D. J. Nesbitt, J. Chem. Phys. 124, 224303 (2006)] are performed. Potential energy surfaces derived from DHTSN for the title reactions are obtained, and compared with that of DHTSN for the reaction F + HC1 -+ HF + C1. Both potential energy surfaces have an early barrier pattern. Integral cross sections and alignments of product molecules HC1 and HF dependent on the internal energy states v and j of reactant molecule C1F are obtained and compared. Translational, vibrational, and rotational energy specific translational enhancements of the reactant molecule CIF of the title reactions are found. Reaction mechanisms of the title reactions according to the respective potential energy contours are further found and explained. Reasons of simultaneous translational and vibrational enhancements are clarified.  相似文献   

16.
This paper investigates the stereodynamics of the reaction He+HD+ by the quasi-classical trajectory(QCT) method using the most accurate AQUILANTI surface [Aquilanti et al 2000 Mol.Phys.98 1835].The distribution P(φr) of dihedral angle and the distribution P(θr) of angle between k and j have been presented at three different collision energies.Four generalized polarization-dependent differential cross-sections(2π/σ)(dσ00/dωt),(2π/σ)(dσ20/dωt),(2π/σ)(dσ22+/dωt),(2π/σ)(dσ21 /dωt) are also calculated.Some interesting results are obtained from the comparison of the stereodynamics of the title reaction at different collision energies.  相似文献   

17.
采用准经典轨线(QCT)方法计算了O(1D)+HBr→OH+Br反应体系的立体动力学反应.基于由Peterson(J.Chem.Phys.113(2000)4598)等人开发的基态势能面上,计算了反应的矢量相关性质,极角p(θ)r及方位角pφ()r以及空间角pθr,φ()r.此外我们还计算了极化微分反应截面(PDDCSs)的分布各矢量性质随各振动量子数变量的变化.结果表明反应受反应物振动量子数影响较大.  相似文献   

18.
The best optimal initial reactant state and collision energy for observing the stereodynamical vector properties of the title reaction in the ground electronic state X2A’ potential energy surface (PES)[Zanchet et al. 2006 J. Phys. Chem. A 110 12017] are theoretically predicted using the quasi-classical trajectory (QCT) method for the first time. The calculated results reveal that the smallest value of the rotational quantum number j, larger vibrational quantum number v, and the lower strength of collision energy should be selected for offering the most obvious picture about the stereodynamical vector properties. Polarization-dependent differential cross sections and the angular momentum alignment distribution, P(θr) and P(Φr) in the center-of-mass frame, are obtained to gain an insight into the alignment and orientation of the product molecules. The rotational angular momentum vector j’ of CO is aligned to be perpendicular to reagent relative velocity k. The product polarizations align along the y axis, pointing to the positive direction of the y axis. A new method is developed to investigate massive reactions with various initial states and to further study the vector properties of the fundamental reactions in detail.  相似文献   

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