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.

scholarly journals Full-Dimensional Ab Initio Potential Energy Surface and Vibrational Energy Levels of Li2H

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 26
Author(s):  
Michiko Ahn Furudate ◽  
Denis Hagebaum-Reignier ◽  
Gwang-Hi Jeung
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Configuration Interaction ◽  
Energy Surface ◽  
Vibrational Energy ◽  
Energy Levels ◽  
Vibrational States ◽  
Configuration Interaction Method ◽  
Vibrational Energy Levels

We built a full-dimensional analytical potential energy surface of the ground electronic state of Li2H from ca. 20,000 ab initio multi-reference configuration interaction calculations, including core–valence correlation effects. The surface is flexible enough to accurately describe the three dissociation channels: Li (2s 2S) + LiH (1Σ+), Li2 (1Σg+) + H (1s 2S) and 2Li (2s 2S) + H (1s 2S). Using a local fit of this surface, we calculated pure (J = 0) vibrational states of Li2H up to the barrier to linearity (ca. 3400 cm−1 above the global minimum) using a vibrational self-consistent field/virtual state configuration interaction method. We found 18 vibrational states below this barrier, with a maximum of 6 quanta in the bending mode, which indicates that Li2H could be spectroscopically observable. Moreover, we show that some of these vibrational states are highly correlated already ca. 1000 cm−1 below the height of the barrier. We hope these calculations can help the assignment of experimental spectra. In addition, the first low-lying excited states of each B1, B2 and A2 symmetry of Li2H were characterized.

Calculation of Rotation–Vibration Energy Levels of the Water Molecule with Near-Experimental Accuracy Based on an ab Initio Potential Energy Surface

2013 ◽  
Vol 117 (39) ◽  
pp. 9633-9643 ◽  
Author(s):  
Oleg L. Polyansky ◽  
Roman I. Ovsyannikov ◽  
Aleksandra A. Kyuberis ◽  
Lorenzo Lodi ◽  
Jonathan Tennyson ◽  
...  
Keyword(s):  
Water Molecule ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Energy Surface ◽  
Energy Levels ◽  
Vibration Energy ◽  
Experimental Accuracy

scholarly journals ExoMol molecular line lists – XXXV. A rotation-vibration line list for hot ammonia

2019 ◽  
Vol 490 (4) ◽  
pp. 4638-4647 ◽  
Author(s):  
Phillip A Coles ◽  
Sergei N Yurchenko ◽  
Jonathan Tennyson
Keyword(s):  
Experimental Data ◽  
Dipole Moment ◽  
High Temperature ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Data Base ◽  
Energy Surface ◽  
Molecular Line ◽  
Line List

ABSTRACT A new hot line list for 14NH3 is presented. The line list CoYuTe was constructed using an accurate, empirically refined potential energy surface and a CCSD(T)/aug-cc-pVQZ ab initio dipole moment surface of ammonia, previously reported. The line list is an improvement of the ammonia line list BYTe. The CoYuTe line list covers wavenumbers up to 20 000 cm−1, i.e. wavelengths beyond 0.5 μm for temperatures up to 1500 K. Comparisons with the high temperature experimental data from the literature show excellent agreement for wavenumbers below 6000 cm−1. The CoYuTe line list contains 16.9 billion transitions and is available from the ExoMol website (www.exomol.com) and the CDS data base.

scholarly journals Ab Initio Ro-Vibrational Structure of the C2? Isotopes of H2O+

1992 ◽  
Vol 45 (5) ◽  
pp. 651 ◽  
Author(s):  
F Wang ◽  
EI von Nagy-Felsobuki
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Force Field ◽  
Ab Initio ◽  
Excellent Agreement ◽  
Energy Surface ◽  
Variational Calculation ◽  
Vibrational Structure ◽  
Vibrational States ◽  
Normal Coordinate

The ro-vibrational structures of the C2" isotopes ofH20+ have been calculated from variational solution of the normal coordinate Eckart-Watson Hamiltonian. The calculations use the discrete ab initio potential energy surface of Weis et al. (1989). Where comparisons can be made, the assignment of the vibrational states is in excellent agreement with experiment and with the ab initio variational calculation of Weis et al., who utilised a different force field and an internal coordinate nuclear Hamiltonian (instead of the Eckart-Watson amiltonian). Furthermore, the calculated rotational levels of the ground and the first excited vibrational states of H20+ and D20+ are in excellent agreement with experiment.

The ab initio potential energy surface and vibrational-rotational energy levels of X 2Σ+ MgOH

2002 ◽  
Vol 117 (4) ◽  
pp. 1529-1535 ◽  
Author(s):  
Jacek Koput ◽  
Stuart Carter ◽  
Kirk A. Peterson ◽  
Giannoula Theodorakopoulos
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Energy Surface ◽  
Energy Levels ◽  
Rotational Energy
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