Energy-dependent stereodynamics for the H(2S)+NH(X3)→H2(X1Σg+)+N(4S) reaction on the improved ZH potential energy surface

2013 ◽  
Vol 91 (6) ◽  
pp. 387-391 ◽  
Author(s):  
Cui-Xia Yao ◽  
Guang-Jiu Zhao
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Cross Sections ◽  
Energy Surface ◽  
Center Of Mass ◽  
Classical Trajectory ◽  
Rotational Alignment ◽  
Title Reaction ◽  
Calculation Results ◽  
Generalized Differential

In this work, quasi-classical trajectory (QCT) calculations have been first carried out for the title reaction on a new global potential energy surface for the lowest quartet electronic state, 4A″. The average rotational alignment factor [P2(j'·k)] as a function of collision energy and the two commonly used polarization dependent generalized differential cross sections PDDCS00, PDDCS20, have been calculated in the center-of-mass (CM) frame, separately. Three angular distributions, P(θr), P(φr), and P(θr, φr) are also calculated to gain insight into the alignment and the orientation of the product molecules. Calculations show that the average rotational alignment factor on the ZH PES is almost invariant with collision energies. The distributions of P(θr) and P(φr) derived from the title reaction indicate that the product polarization is strong. Validity of the QCT calculation has been examined and proven in the comparison with the quantum-wave-packet calculation results. Comparisons with available quasi-classical trajectory results are made and discussed.

scholarly journals The stereodynamics study on the isotopic substitution C + SH(D, T) → H(D, T) + CS reactions on the new HCS(X2A′ ) potential energy surface

2017 ◽  
Vol 95 (12) ◽  
pp. 1219-1224 ◽  
Author(s):  
Lu-Lu Zhang ◽  
Shou-Bao Gao ◽  
Yu-Zhi Song ◽  
Da-Guang Yue ◽  
Guo-Meng Chen ◽  
...  
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Cross Sections ◽  
Energy Surface ◽  
Substitution Effect ◽  
Classical Trajectory ◽  
Distribution Functions ◽  
Isotopic Substitution ◽  
Angle Distribution ◽  
Reagent Molecule

The quasi-classical trajectory calculations are carried out to investigate the isotopic substitution effect on title reactions based on the recently developed, accurate potential energy surface of the HCS(X2[Formula: see text]) (Song, Zhang, et al. Sci. Rep. 6, 37734 (2016)). The total integral cross sections (ICSs) and vibrational state resolved ICSs are obtained for C + SH(D, T) → H(D, T) + CS reactions. In addition, differential cross sections and two angle distribution functions P(θr), P([Formula: see text]) at different collision energies are investigated. It is found that the peaks of P(θr) and P([Formula: see text]) become lower with the reagent molecule SH turning into SD and ST.

Stereodynamics investigation of F + HO → HF + O(1D) on the ground singlet potential energy surface by means of the quasi-classical trajectory method

2014 ◽  
Vol 92 (3) ◽  
pp. 250-256 ◽  
Author(s):  
Dan Zhao ◽  
Xiaohu He ◽  
Wei Guo
Keyword(s):  
Angular Momentum ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Collision Energy ◽  
Energy Surface ◽  
Vibrational Excitation ◽  
Classical Trajectory ◽  
Rotational Excitation ◽  
Title Reaction ◽  
Trajectory Method

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.

INFLUENCE OF THE COLLISION ENERGY ON STEREODYNAMICS OF THE F + LiH (v = 0, j = 0) → LiF + H REACTION

2011 ◽  
Vol 10 (04) ◽  
pp. 401-410
Author(s):  
TAO WANG ◽  
XIANGYANG MIAO
Keyword(s):  
Angular Momentum ◽  
Angular Distribution ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Dihedral Angle ◽  
Collision Energy ◽  
Energy Surface ◽  
Classical Trajectory ◽  
Angle Distribution ◽  
Title Reaction

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.

A QUASI-CLASSICAL TRAJECTORY STUDY ON STEREODYNAMICS OF THE F + HCl (v = 0, j = 0) → HF + Cl REACTION

2012 ◽  
Vol 11 (03) ◽  
pp. 663-674 ◽  
Author(s):  
XIAN-FANG YUE ◽  
PEI FENG
Keyword(s):  
Angular Momentum ◽  
Cross Sections ◽  
Ground State ◽  
Energy Surface ◽  
Center Of Mass ◽  
Classical Trajectory ◽  
Polar Coordinates ◽  
Angular Distributions ◽  
Title Reaction ◽  
Mass Frame

Quasiclassical trajectory (QCT) calculations for the title reaction are carried out by employing the recent developed accurate potential energy surface of the 12A′ ground state. Two angular distributions, P(θr) and P(ϕr), with θr, ϕr being the polar angles of the product angular momentum, and two commonly used polarization dependent differential cross sections, (2π/σ)(dσ00/dωt) and (2π/σ)(dσ20/dωt), with ωt being the polar coordinates of the product velocity, are generated in the center-of-mass frame. It was found that the product rotational angular momentum j′ is not only aligned, but also oriented along the negative direction of y-axis. We also investigated the product state distributions in the present work, and found that the vibrational and rotational state distributions are inverted. Influences of collision energies on the product polarization and state distributions are also shown and discussed.

THEORETICAL STUDY OF QUASI-CLASSICAL CALCULATIONS FOR THE REACTION Sr + CH3Br

2010 ◽  
Vol 09 (02) ◽  
pp. 487-493 ◽  
Author(s):  
YA-MIN LI ◽  
SHUO WANG
Keyword(s):  
Angular Distribution ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Theoretical Study ◽  
Exothermic Reaction ◽  
Chem Phys ◽  
Classical Trajectory ◽  
Good Comparison ◽  
Calculation Results

The first quasi-classical trajectory (QCT) calculation for the exothermic reaction Sr + CH3Br is carried out based on a constructed London–Eyring–Polanyi–Sato (LEPS) potential energy surface (PES). By QCT calculation, the product SrBr vibration distributions are obtained. The result is in good comparison with the experimental one by Keijzer JF et al. [Chem. Phys.207:261, 1996]. Furthermore, the reaction product SrBr angular distribution and rotational alignment are also obtained. The products are dominantly forward-scattered and the alignment effect is obvious. Fast dynamics mechanism is proposed upon the calculation results.

EFFECT OF THE REACTANT ALIGNMENT ON STEREODYNAMICS FOR THE REACTION F + OH

2011 ◽  
Vol 10 (04) ◽  
pp. 531-539 ◽  
Author(s):  
JUAN ZHAO
Keyword(s):  
Potential Energy ◽  
Triplet State ◽  
Cross Sections ◽  
Differential Cross ◽  
Energy Surface ◽  
Theoretical Foundation ◽  
Incident Angle ◽  
Center Of Mass ◽  
Classical Trajectory ◽  
Adiabatic Potential Energy Surface

Quasi-classical trajectory (QCT) calculations are performed for the reaction F + OH → HF + O based on the adiabatic potential-energy surface (PES) of the 13A″ triplet state. The reaction probability as a function of incident angle has been presented. The differential cross sections (DCSs), the distribution of angle between k and j′, P(θr) and the distribution of dihedral angle denoting k – k′ – j′ correlation, P(ϕr) have also been calculated at the different incident angles in the center-of-mass (CM) frame, respectively. The effects of reactant alignment on stereodynamics of the reaction are firstly revealed, which provides the theoretical foundation for the related experiment and enriches the theories of the stereodynamics.

scholarly journals Quasi-Classical Trajectory Study of the CN + NH3 Reaction Based on a Global Potential Energy Surface

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 994
Author(s):  
Joaquin Espinosa-Garcia ◽  
Cipriano Rangel ◽  
Moises Garcia-Chamorro ◽  
Jose C. Corchado
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Energy Surface ◽  
Classical Trajectory ◽  
Theoretical Studies ◽  
Rotational Excitation ◽  
Title Reaction ◽  
Deep Wells ◽  
Kinetics And Dynamics

Based on a combination of valence-bond and molecular mechanics functions which were fitted to high-level ab initio calculations, we constructed an analytical full-dimensional potential energy surface, named PES-2020, for the hydrogen abstraction title reaction for the first time. This surface is symmetrical with respect to the permutation of the three hydrogens in ammonia, it presents numerical gradients and it improves the description presented by previous theoretical studies. In order to analyze its quality and accuracy, stringent tests were performed, exhaustive kinetics and dynamics studies were carried out using quasi-classical trajectory calculations, and the results were compared with the available experimental evidence. Firstly, the properties (geometry, vibrational frequency and energy) of all stationary points were found to reasonably reproduce the ab initio information used as input; due to the complicated topology with deep wells in the entrance and exit channels and a “submerged” transition state, the description of the intermediate complexes was poorer, although it was adequate to reasonably simulate the kinetics and dynamics of the title reaction. Secondly, in the kinetics study, the rate constants simulated the experimental data in the wide temperature range of 25–700 K, improving the description presented by previous theoretical studies. In addition, while previous studies failed in the description of the kinetic isotope effects, our results reproduced the experimental information. Finally, in the dynamics study, we analyzed the role of the vibrational and rotational excitation of the CN(v,j) reactant and product angular scattering distribution. We found that vibrational excitation by one quantum slightly increased reactivity, thus reproducing the only experimental measurement, while rotational excitation strongly decreased reactivity. The scattering distribution presented a forward-backward shape, associated with the presence of deep wells along the reaction path. These last two findings await experimental confirmation.

THEORETICAL STUDY OF THE STEREO-DYNAMICS OF THE REACTION O + HCl → ClO + H

2011 ◽  
Vol 10 (01) ◽  
pp. 1-7 ◽  
Author(s):  
QIANG WEI ◽  
YING KE XIE ◽  
WEN LIN FENG
Keyword(s):  
Angular Momentum ◽  
Cross Sections ◽  
Collision Energy ◽  
Energy Surface ◽  
Theoretical Study ◽  
Center Of Mass ◽  
Classical Trajectory ◽  
Title Reaction ◽  
Mass Frame ◽  
Product Vector

Quasi-classical trajectory (QCT) method is used to study the stereo-dynamics of the title reaction on the ground 1 1A′ potential energy surface (PES). Differential cross-sections (DCSs) and alignments of the product rotational angular momentum for the reaction are reported. The influence of collision energy on the product vector properties is also studied in the present work. The distribution of angle between k and j′, P(θr), the distribution of dihedral angle denoting k-k′-j′ correlation, P(ϕr) ⋅ (2π/σ)( d σ00/ d ωt), (2π/σ)( d σ20/ d ωt), (2π/σ)( d σ22+/ d ωt) and (2π/σ)(dσ21-/dωt) have been calculated in the center of mass frame, respectively.

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