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Coudert LH, Chitarra O, Spaniol JT, Loison JC, Martin-Drumel MA, Pirali O. Tunneling motion and splitting in the CH 2OH radical: (Sub-)millimeter wave spectrum analysis. J Chem Phys 2022; 156:244301. [DOI: 10.1063/5.0095242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The (sub-)millimeter wave spectrum of the non-rigid CH2OH radical is investigated both experimentally and theoretically. Ab initio calculations are carried out to quantitatively characterize its potential energy surface as a function of the two large amplitude ∠H1COH and ∠H2COH dihedral angles. It is shown that the radical displays a large amplitude torsional-like motion of its CH2 group with respect to the OH group. The rotation–torsion levels computed with the help of a 4D Hamiltonian accounting for this torsional-like motion and for the overall rotation exhibit a tunneling splitting, in agreement with recent experimental investigations, and a strong rotational dependence of this tunneling splitting on the rotational quantum number K a due to the rotation–torsion Coriolis coupling. Based on an internal axis method approach, a fitting Hamiltonian accounting for tunneling effects and for the fine and hyperfine structure is built and applied to the fitting of the new (sub)-millimeter wave transitions measured in this work along with previously available high-resolution data. 778 frequencies and wavenumbers are reproduced with a unitless standard deviation of 0.79 using 27 parameters. The N = 0 tunneling splitting, which could not be determined unambiguously in the previous high-resolution investigations, is determined based on its rotational dependence.
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Affiliation(s)
- L. H. Coudert
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d’Orsay, 91405 Orsay, France
| | - O. Chitarra
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d’Orsay, 91405 Orsay, France
| | - J.-T. Spaniol
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d’Orsay, 91405 Orsay, France
| | - J.-C. Loison
- Institut des Sciences Moléculaires, UMR 5255 CNRS - Université de Bordeaux, Bât. A12, 351 Cours de la Libération, 33405 Talence Cedex, France
| | - M.-A. Martin-Drumel
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d’Orsay, 91405 Orsay, France
| | - O. Pirali
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d’Orsay, 91405 Orsay, France
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Kannis CS, Suarez J, Rakitzis TP. Macroscopic production of spin-polarised hydrogen atoms from the IR-excitation and photodissociation of molecular beams. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1975053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- C. S. Kannis
- Institute for Nuclear Physics, Forschungszentrum Jülich, Jülich, Germany
- Department of Physics, University of Crete, Herakleio, Greece
| | - J. Suarez
- Departamento de Quimica, Modulo 13, Universidad Autonoma de Madrid, Cantoblanco, Madrid, Spain
| | - T. P. Rakitzis
- Department of Physics, University of Crete, Herakleio, Greece
- Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, Heraklion, Crete, Greece
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Bross DH, Yu HG, Harding LB, Ruscic B. Active Thermochemical Tables: The Partition Function of Hydroxymethyl (CH2OH) Revisited. J Phys Chem A 2019; 123:4212-4231. [DOI: 10.1021/acs.jpca.9b02295] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David H. Bross
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Hua-Gen Yu
- Division of Chemistry, Department of Energy and Photon Sciences, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Lawrence B. Harding
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Branko Ruscic
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Consortium for Advanced Science and Engineering, The University of Chicago, Chicago, Illinois 60637, United States
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