Effect of collision energy on cross sections and product alignments for the C(1D) + H2 (v = 0, j = 0) insertion reactions

2010 ◽  
Vol 88 (5) ◽  
pp. 453-457 ◽  
Author(s):  
Lihua Kang ◽  
Bin Dai

Quasi-classical trajectory (QCT) calculations of total reaction probabilities and vibrationally state-resolved reaction probabilities at total angular momentum J = 0 as a function of collision energy for the C(1D) + H2 (v = 0, j = 0) reactions have been performed on an ab initio potential-energy surface [ J. Chem. Phys. 2001, 115, 10701]. In addition, the integral cross sections as a function of collision energy have been carried out for the same reaction. The product rotational alignments have also been calculated, which are almost invariant with respect to collision energies.


2011 ◽  
Vol 89 (10) ◽  
pp. 1283-1288
Author(s):  
Li-hua Kang ◽  
Shan-zheng Zhang ◽  
Mingyuan Zhu ◽  
Bin Dai

The stereodynamics of the title reaction on the ab initio1A′ potential energy surface (PES) (B. Bussery-Honvault, P. Honvault, and J.-M. Launay. 2001. J. Chem. Phys. 115: 10701) at a collision energy of 16 kJ/mol have been studied using quasi-classical trajectory (QCT) method. Vector properties including angular momentum alignment parameters and four polarization-dependent differential cross sections (PDDCS) of the product CH are presented. Furthermore, the influence of reagent vibrational and rotational excitations on the product vector properties have also been studied in the present work. The calculated results indicate that the angle distributions of the CH product are mainly dominated by backward–forward scattering.



2012 ◽  
Vol 90 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Ningjiu Zhao ◽  
Yufang Liu

In this work, we employed the quasi-classical trajectory (QCT) method to study the vector correlations and the influence of the reagent initial rotational quantum number j for the reaction He + T2+ (v = 0, j = 0–3) → HeT+ + T on a new potential energy surface (PES). The PES was improved by Aquilanti co-workers (Chem. Phys. Lett. 2009. 469: 26–30). The polarization-dependent differential cross sections (PDDCSs) and the distributions of P(θr), P([Formula: see text]r), and P(θr, [Formula: see text]r) are presented in this work. The plots of the PDDCSs provide us with abundant information about the distribution of the product angular momentum polarization. The P(θr) is used to describe the correlation between k (the relative velocity of the reagent) and j′ (the product rotational angular momentum). The distribution of dihedral angle P([Formula: see text]r) shows the k–k′–j′ (k′ refers to the relative velocity of the product) correlation. The PDDCS calculations illustrate that the product of this reaction is mainly backward scatter and it has the strongest polarization in the backward and sideways scattering directions. At the same time, the results of the P([Formula: see text]r) demonstrate that the product HeT+ tends to be oriented along the positive direction of the y axis and it tends to rotate right-handedly in planes parallel to the scattering plane. Moreover, the distribution of the P(θr) manifests that the product angular momentum is aligned along different directions relative to k. The direction of the product alignment may be perpendicular, opposite, or parallel to k. Moreover, our calculations are independent of the initial rotational quantum number.



2018 ◽  
Vol 96 (8) ◽  
pp. 926-932 ◽  
Author(s):  
Guan-Qing Ren ◽  
Ai-Ping Fu ◽  
Shu-Ping Yuan ◽  
Tian-Shu Chu

To investigate the dynamics mechanism of the Br + HgBr → Br2 + Hg reaction, the quasi-classical trajectory calculations are performed on Balabanov’s potential energy surface (PES) of ground electronic state. Both the scalar and vector properties are investigated to recognize the dynamics of the title reaction. Reaction probability for the total angular momentum quantum number J = 0 is determined at the collision energies (denoted as Ec) in a range of 1–25 kcal/mol, and the product vibrational distributions are given and compared between Ec = 20 and 40 kcal/mol. Other calculation values characterizing product polarizations including polarization-dependent differential cross sections (PDDCSs), distributions of P(θr), P([Formula: see text]), and P(θr, [Formula: see text]), are all discussed and compared between the two different collision energies in detail to analyze the alignment and orientation characteristics. It is revealed that the products prefer forward scattering and the PDDCSs are anisotropic in the whole range of the scattering angle. The product rotational angular momentum j′ shows a tendency to align perpendicular to the reagent relative velocity k. In fact, the product polarization of the title reaction is weak at both collision energies. In terms of horizontal comparison, the alignment is slightly stronger but the orientation is even less remarkable at higher collision energy.



2014 ◽  
Vol 92 (3) ◽  
pp. 250-256 ◽  
Author(s):  
Dan Zhao ◽  
Xiaohu He ◽  
Wei Guo

The stereodynamics calculation of F + HO → HF + O(1D) was carried out using the quasi-classical trajectory method on the 11A′ potential energy surface provided by Gomez-Carrasco et al. (Chem. Phys. Lett. 2007, 435, 188). The effect of the collision energy, isotopic substitution, and different initial ro-vibrational states on the reaction is discussed. It is found that for the initial ground state of HO (v = 0, j = 0), the degree of the forward scattering and the product polarizations remarkably change as the collision energy varies. Isotopic effect leads to the increase of alignment and decrease of orientation of product rotational angular momentum. Moreover, the P(θr) distribution and P(φr) distribution change noticeably by varying the initial vibrational number. The initial vibrational excitation plays a more important role in the enhancement of alignment and orientation distribution of j′ for the title reaction. Although the influence of the initial rotational excitation effect on the aligned and oriented distribution of product is not stronger than that of the initial vibrational excitation effect, the initial rotational excitation makes the alignment of the product rotational angular momentum decrease to some extent. The probabilities show that the reactivity of the title reaction strongly depends on the initial vibrational state.



2011 ◽  
Vol 10 (04) ◽  
pp. 401-410
Author(s):  
TAO WANG ◽  
XIANGYANG MIAO

The stereodynamics of the title reaction based on the ground 2A′ potential energy surface (PES) has been investigated using the method of the quasi-classical trajectory (QCT) at different collision energies (23 kcal/mol, 35 kcal/mol and 46 kcal/mol). The vector properties of the angular momentum (described by the distribution of K - J′P(θr), the dihedral angle distribution of K - K′ - J′P(φr) and the angular distribution P(θr, ϕr)) and the four PDDCSs [(2π/σ)(dσ00/dωt), (2π/σ)(dσ20/dωt), (2π/σ)(dσ22+/dωt), (2π/σ)(dσ21-/dωt)] of the product LiF at each collision energy have been presented, respectively. Further, the collision energy effects on the behavior of the product LiF have been discussed and studied.



2011 ◽  
Vol 10 (02) ◽  
pp. 147-163
Author(s):  
LI ZHANG ◽  
CHAO-YONG ZHU ◽  
GANG JIANG ◽  
CHAOYUAN ZHU ◽  
Z. H. ZHU

A quasiclassical trajectory method was employed to study reaction Ge+H 2 (v=0, j=0) and reverse reaction H+GeH (v=0, j=0) on an analytical potential energy surface obtained from simplified many-body expansion method with fitting to B3P86/CC-pVTZ calculations around a global minimum and a long-range van de Waals well plus spectroscopy data for diatomic molecules GeH and H2 . Reaction probabilities from both reaction and reverse reaction were calculated. Dominant reaction is complex-forming reaction Ge+H2 (v=0, j=0) → GeH2 , and its cross section is 10 times bigger than that of complex-forming reaction from the reverse reaction. There is no threshold effect for complex-forming reaction and the cross sections for both complex-forming reactions decrease with the increase of collision energy. Life time of complex is shown to be decreasing with increase of collision energy. Dominant reverse reaction is reaction H + GeH (v=0,j=0) → Ge+H2 ; the reaction probability decreases with the increase of collision energy and differential cross section shows that this reverse reaction has almost equal angular distribution at low collision energy and mostly forward scattering at high collision energy.



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