F(2P) + C2H6 → HF + C2H5 kinetics study based on a new analytical potential energy surface

2018 ◽  
Vol 20 (30) ◽  
pp. 19860-19870 ◽  
Author(s):  
J. Espinosa-Garcia ◽  
J. C. Corchado ◽  
M. Garcia-Chamorro ◽  
C. Rangel

An exhaustive kinetics study was performed for the title reaction using two theoretical approaches: variational transition-state theory and quasi-classical trajectory calculations, based on an original new analytical full-dimensional potential energy surface, named PES-2018, which has been fitted to high-level ab initio calculations.

Author(s):  
J. Espinosa-Garcia ◽  
Jose Carlos Corchado

For the theoretical study of the title reaction, an analytical full-dimensional potential energy surface named PES-2021 was developed for the first time, by fitting high-level explicitly-correlated ab initio data. This...


2019 ◽  
Vol 21 (24) ◽  
pp. 13347-13355 ◽  
Author(s):  
Joaquin Espinosa-Garcia ◽  
Moises Garcia-Chamorro ◽  
Jose C. Corchado

Using as input data high-level structure electronic calculations, a new full-dimensional analytical potential energy surface (PES), named PES-2018, was developed for the title reaction, which is a valence bond/molecular mechanics based surface that depends on a set of adjustable parameters.


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.


Author(s):  
Changjian Xie ◽  
Xinguo Liu ◽  
Brendan C. Sweeny ◽  
Thomas M. Miller ◽  
Shaun G. Ard ◽  
...  

We report a joint experimental–theoretical study of the F –  + HCl → HF + Cl − reaction kinetics. The experimental measurement of the rate coefficient at several temperatures was made using the selected ion flow tube method. Theoretical rate coefficients are calculated using the quasi-classical trajectory method on a newly developed global potential energy surface, obtained by fitting a large number of high-level ab initio points with augmentation of long-range electrostatic terms. In addition to good agreement between experiment and theory, analyses suggest that the ion–molecule reaction rate is significantly affected by shorter-range interactions, in addition to the traditionally recognized ion–dipole and ion–induced dipole terms. Furthermore, the statistical nature of the reaction is assessed by comparing the measured and calculated HF product vibrational state distributions to that predicted by the phase space theory. This article is part of the theme issue ‘Modern theoretical chemistry’.


2013 ◽  
Vol 117 (32) ◽  
pp. 7502-7522 ◽  
Author(s):  
Roberto Marquardt ◽  
Kenneth Sagui ◽  
Jingjing Zheng ◽  
Walter Thiel ◽  
David Luckhaus ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 994
Author(s):  
Joaquin Espinosa-Garcia ◽  
Cipriano Rangel ◽  
Moises Garcia-Chamorro ◽  
Jose C. Corchado

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.


Sign in / Sign up

Export Citation Format

Share Document