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 Computational study of the rovibrational spectrum of H2O-HF

2021 ◽  
Author(s):  
Dominika VIGLASKA ◽  
Xiao-Gang Wang ◽  
Tucker CARRINGTON ◽  
David Tew
Keyword(s):  
Experimental Data ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Energy Surface ◽  
Computational Study ◽  
Energy Levels ◽  
Dissociation Limit ◽  
Lanczos Algorithm ◽  
Vibrational States

In this paper we report rovibrational energy levels, transition frequencies, and intensities computed for H2O-HF using a new ab initio potential energy surface and compare with available experimental data. We use the rigid monomer approximation. A G4 symmetry-adapted Lanczos algorithm and an uncoupled product basis are employed. The rovibrational levels are computed up to J = 4. The new analytic 9-D potential is �t to 39771 counterpoise corrected CCSD(T)(F12*)/augcc- pVTZ energies and reduces to the sum of uncoupled H2O and HF potentials in the dissociation limit. On the new potential better agreement with experiment is obtained by re-assigning the R(1) transitions of two vibrational states.

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.

scholarly journals A very high accuracy potential energy surface for H3

1999 ◽  
Vol 1 (6) ◽  
pp. 929-937 ◽  
Author(s):  
Y.-S Mark Wu ◽  
Aron Kuppermann ◽  
James B. Anderson
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
High Accuracy ◽  
Very High

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.

scholarly journals Theoretical Study on Pentiptycene Molecular Brake: Photoinduced Isomerization and Photoinduced Electron Transfer

2021 ◽  
Author(s):  
Hailong Wang ◽  
Qiuping Guan ◽  
Xueye Wang
Keyword(s):  
Electron Transfer ◽  
Double Bond ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Basis Set ◽  
Isomerization Reaction ◽  
Excitation Energies ◽  
Dft Computations ◽  
Molecular Brake

Abstract The isomerization of the double bond plays an important role in the braking and de-braking of the light-driven molecular brake. Therefore, the Pp-type light-controlled molecular brake system containing the C=C double bond was theoretically studied. Combining the 6-31G(d) basis set, the ωB97XD functional with dispersion correction was applied to implement the (E)-configuration and (Z)-configuration initial optimization. Next, using the 6-311G(d,p) basis set, the relaxed potential energy surface scans of the rotation angle were operated, and then the optimization calculations of the transition states at the extremum high points. Analyzing the stagnation points and the rotational transition state on the MEPs, the rotation mechanism and basic energy parameters of the molecular brake were obtained. Then the DFT computations at ground states and the TD-DFT computations of vertical excitation energy was put into practice at the accuracy of the def-TZVP basis set for the two configurations, and using the natural transition orbital (NTOs) analyses combining the excitation energies and absorption spectrums of the molecules, the electronic transition characteristics and electron transfer properties of light-driven molecular brake were studied. Afterwards, in order to investigate the photo-induced isomerization reaction, the C=C double bond was scanned on the relaxed potential energy surface, and the intermediates of the isomerization reaction was searched and analyzed, thus, the braking mechanism of the light-driven molecular brake was proposed.

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
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