On the use of the sudden approximation for vibrational excitation in high‐energy collisions, and the sensitivity of the results to the choice of potential energy surface

1976 ◽  
Vol 65 (12) ◽  
pp. 5532-5533 ◽  
Author(s):  
Rex T. Skodje ◽  
W. Ronald Gentry ◽  
Clayton F. Giese
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Vibrational Excitation ◽  
High Energy ◽  
Sudden Approximation ◽  
High Energy Collisions

scholarly journals Bifurcation of Dividing Surfaces Constructed from a Pitchfork Bifurcation of Periodic Orbits in a Symmetric Potential Energy Surface with a Post-Transition-State Bifurcation

2021 ◽  
Vol 31 (14) ◽  
Author(s):  
M. Katsanikas ◽  
M. Agaoglou ◽  
S. Wiggins
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Periodic Orbits ◽  
Lower Energy ◽  
Degrees Of Freedom ◽  
Energy Surface ◽  
Pitchfork Bifurcation ◽  
High Energy ◽  
Symmetric Potential ◽  
The Family

In this work, we analyze the bifurcation of dividing surfaces that occurs as a result of a pitchfork bifurcation of periodic orbits in a two degrees of freedom Hamiltonian System. The potential energy surface of the system that we consider has four critical points: two minima, a high energy saddle and a lower energy saddle separating two wells (minima). In this paper, we study the structure, the range, and the minimum and maximum extent of the periodic orbit dividing surfaces of the family of periodic orbits of the lower saddle as a function of the total energy.

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.

Significant effects of vibrational excitation of reactant in K + H2 → H + KH reaction based on a new neural network potential energy surface

2018 ◽  
Vol 20 (31) ◽  
pp. 20641-20649 ◽  
Author(s):  
Jiuchuang Yuan ◽  
Zhixin Duan ◽  
Shufen Wang ◽  
Jianyong Liu ◽  
Keli Han
Keyword(s):  
Neural Network ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Vibrational Energy ◽  
Vibrational Excitation ◽  
Translational Energy

Reactant vibrational energy in K + H2 reaction is significantly more effective in promoting the reaction than translational energy.

Large scale vibrational calculations on IVR in S0 thiophosgene

2016 ◽  
Vol 15 (01) ◽  
pp. 1650005 ◽  
Author(s):  
Svetoslav Rashev ◽  
David C. Moule
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Large Scale ◽  
Energy Surface ◽  
Vibrational Excitation ◽  
Dissociation Limit ◽  
Excitation Energies ◽  
Local Coupling ◽  
Very High

In this work, using a recently derived refined potential energy surface for [Formula: see text] thiophosgene, we perform large scale vibrational calculations to explore the IVR characteristics and vibrational mixing at very high vibrational excitation energies, ranging up to the dissociation limit (at [Formula: see text]20,000[Formula: see text]cm[Formula: see text]). The results from our calculations have been compared to the conclusions based on the available experimentally measured dataset (obtained from SEP and LIF spectra) as well as to the conclusions from the analyses by other authors using local coupling models.

scholarly journals A semi-empirical potential energy surface and line list for H<sub>2</sub><sup>16</sup>O extending into the near-ultraviolet

2020 ◽  
Vol 20 (16) ◽  
pp. 10015-10027 ◽  
Author(s):  
Eamon K. Conway ◽  
Iouli E. Gordon ◽  
Jonathan Tennyson ◽  
Oleg L. Polyansky ◽  
Sergei N. Yurchenko ◽  
...  
Keyword(s):  
Water Molecule ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Vibrational Excitation ◽  
Special Importance ◽  
Line List ◽  
Empirical Potential ◽  
Near Ultraviolet ◽  
Semi Empirical

Abstract. Accurate reference spectroscopic information for the water molecule from the microwave to the near-ultraviolet is of paramount importance in atmospheric research. A semi-empirical potential energy surface for the ground electronic state of H216O has been created by refining almost 4000 experimentally determined energy levels. These states extend into regions with large values of rotational and vibrational excitation. For all states considered in our refinement procedure, which extend to 37 000 cm−1 and J=20 (total angular momentum), the average root-mean-square deviation is approximately 0.05 cm−1. This potential energy surface offers significant improvements when compared to recent models by accurately predicting states possessing high values of J. This feature will offer significant improvements in calculated line positions for high-temperature spectra where transitions between high J states become more prominent. Combining this potential with the latest dipole moment surface for water vapour, a line list has been calculated which extends reliably to 37 000 cm−1. Obtaining reliable results in the ultraviolet is of special importance as it is a challenging spectral region for the water molecule both experimentally and theoretically. Comparisons are made against several experimental sources of cross sections in the near-ultraviolet and discrepancies are observed. In the near-ultraviolet our calculations are in agreement with recent atmospheric retrievals and the upper limit obtained using broadband spectroscopy by Wilson et al. (2016, p. 194), but they do not support recent suggestions of very strong absorption in this region.

Anab initio potential energy surface and dynamics calculations for vibrational excitation of I2 by He

1985 ◽  
Vol 68 (1) ◽  
pp. 23-44 ◽  
Author(s):  
Franklin B. Brown ◽  
David W. Schwenke ◽  
Donald G. Truhlar
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Vibrational Excitation

Semiclassical study of sudden approximations for rotationally inelastic scattering of Ar + HF

1994 ◽  
Vol 72 (3) ◽  
pp. 985-994 ◽  
Author(s):  
James J. C. Barrett ◽  
Howard R. Mayne ◽  
Mark Keil ◽  
Leslie J. Rawluk
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Inelastic Scattering ◽  
Cross Sections ◽  
Differential Cross ◽  
Infinite Order ◽  
Energy Surface ◽  
Differential Cross Sections ◽  
Sudden Approximation ◽  
Rotationally Inelastic Scattering

"Exact" quantum close coupled (CC) and infinite-order sudden approximation (IOSA) calculations have been carried out for the Ar + HF system on an accurate potential energy surface. The differential cross sections from the IOSA calculations show marked differences from the CC results. We find that the energy sudden component of the IOSA breaks down in a different manner for small and large impact parameters, significantly shifting and distorting the state-to-state differential cross sections. We also find that the centrifugal sudden approximation alone reproduces all features of the full semiclassical calculations quite faithfully. Through the use of several rotational sudden approximations, including a semiclassical version of the IOSA, we identify how the differences between the CC and IOSA results arise.

Potential energy surface for high-energy N + N2 collisions

2021 ◽  
Author(s):  
Zoltán Varga ◽  
Donald G. Truhlar
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Molecular Simulations ◽  
High Energy ◽  
Molecular Collisions ◽  
Physical Insight ◽  
Insight Into

Potential energy surface calculations yield physical insight into the structure of intermediates and the dynamics of molecular collisions, and they are the first step toward molecular simulations that provide physical...

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