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Campargue A, Karlovets EV, Vasilchenko SS, Turbet M. The high resolution absorption spectrum of methane in the 10 800-14 000 cm -1 region: literature review, new results and perspectives. Phys Chem Chem Phys 2023. [PMID: 38038983 DOI: 10.1039/d3cp02385k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
The recent development of high resolution spectrographs for exoplanetary research in the visible range makes suitable an improvement of our knowledge of the high resolution spectrum of methane. In this contribution, the weak and highly congested absorption spectrum of methane in the 10 800-14 000 cm-1 region (0.71-0.93 μm) is considered on the basis of (i) an exhaustive review of the literature over the lasts decades, (ii) the analysis of a spectrum recorded at Kitt Peak by Fourier transform spectroscopy at room temperature, (iii) a very high sensitivity spectrum recorded by cavity ring down spectroscopy near 760 nm. The line list retrieved from the Kitt Peak spectrum includes 12 800 lines between 10 802 and 13 922 cm-1. Together with the CRDS line list in the 13 060-13 300 cm-1 interval (about 2650 lines), the reported FTS dataset represents the first high resolution extensive intensity measurements of methane for wavenumbers above 11 502 cm-1. A very good agreement between our Kitt Peak line list and HITRAN list is found in the 10 800-11 502 cm-1 interval. The "quasi-continuum" absorption background underlying the congested spectrum around 11 200 cm-1 is quantitatively evaluated to about 42% of the absorption by CH4 lines. Previous laser-based investigations are critically reviewed by comparison to the FTS and CRDS experimental data retrieved in the present work. The review of the studies of the minor isotopologues (13CH4, CH3D, CH2D2, and CHD3) is also presented. Intensity comparison with band models used for planetary applications is discussed and confirms the importance of the "quasi-continuum" absorption in the methane spectrum at room temperature. The comparison to the TheoReTs line list obtained by ab initio calculations gives valuable hints for future assignments but the TheoReTS line positions are not sufficiently accurate for application to high resolution exoplanetary spectra in the region. From the various comparisons and results obtained in this work, we conclude that the high frequency absorption spectrum of methane deserves to be revisited by modern cavity-enhanced absorption techniques to fulfil needs both for future analysis of high resolution exoplanetary spectra and for theoretical analysis.
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Affiliation(s)
- A Campargue
- University Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France.
| | - E V Karlovets
- Tomsk State University, Department of Optics and Spectroscopy, 36, Lenin Avenue, 634050, Tomsk, Russia
| | - S S Vasilchenko
- V.E. Zuev Institute of Atmospheric Optics, 1, Academician Zuev Square, 634055 Tomsk, Russia
| | - M Turbet
- Laboratoire de Météorologie Dynamique/IPSL, CNRS, Sorbonne Université, École Normale Supérieure, Université PSL, Ecole Polytechnique, Institut Polytechnique de Paris, 75005 Paris, France
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2
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Zhao Z, Chen J, Zhang Z, Zhang DH, Wang XG, Carrington T, Gatti F. Computing energy levels of CH4, CHD3, CH3D, and CH3F with a direct product basis and coordinates based on the methyl subsystem. J Chem Phys 2018; 148:074113. [DOI: 10.1063/1.5019323] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Zhiqiang Zhao
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Jun Chen
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Siming South Road 422, 361005 Xiamen, China
| | - Zhaojun Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Dong H. Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Xiao-Gang Wang
- Chemistry Department, Queen’s University, Kingston, Ontario K7L 3N6, Canada
| | - Tucker Carrington
- Chemistry Department, Queen’s University, Kingston, Ontario K7L 3N6, Canada
| | - Fabien Gatti
- ISMO, Institut des Sciences Moléculaires d’Orsay - UMR 8214 CNRS/Université Paris-Sud, F-91405 Orsay, France
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3
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Owens A, Yurchenko SN, Yachmenev A, Tennyson J, Thiel W. A highly accurate ab initio potential energy surface for methane. J Chem Phys 2016; 145:104305. [DOI: 10.1063/1.4962261] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Alec Owens
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Sergei N. Yurchenko
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - Andrey Yachmenev
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - Jonathan Tennyson
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - Walter Thiel
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
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4
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Zhao Z, Chen J, Zhang Z, Zhang DH, Lauvergnat D, Gatti F. Full-dimensional vibrational calculations of five-atom molecules using a combination of Radau and Jacobi coordinates: Applications to methane and fluoromethane. J Chem Phys 2016; 144:204302. [DOI: 10.1063/1.4950028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Zhiqiang Zhao
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Jun Chen
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Zhaojun Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Dong H. Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - David Lauvergnat
- CNRS, Laboratoire de Chimie Physique (UMR 8000), Université Paris-Sud, F-91405 Orsay, France
| | - Fabien Gatti
- CTMM, Institut Charles Gerhardt (UMR 5253), CC 1501, Université Montpellier, F-34095 Montpellier, Cedex 05, France
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5
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Herman M, Földes T, Didriche K, Lauzin C, Vanfleteren T. Overtone spectroscopy of molecular complexes containing small polyatomic molecules. INT REV PHYS CHEM 2016. [DOI: 10.1080/0144235x.2016.1171039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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6
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Amyay B, Louviot M, Pirali O, Georges R, Vander Auwera J, Boudon V. Global analysis of the high temperature infrared emission spectrum of 12CH4 in the dyad (ν2/ν4) region. J Chem Phys 2016; 144:024312. [DOI: 10.1063/1.4939521] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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7
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Yu HG. Multi-layer Lanczos iteration approach to calculations of vibrational energies and dipole transition intensities for polyatomic molecules. J Chem Phys 2015; 142:044106. [DOI: 10.1063/1.4906492] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Hua-Gen Yu
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973-5000, USA
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8
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Yu HG. Neural network iterative diagonalization method to solve eigenvalue problems in quantum mechanics. Phys Chem Chem Phys 2015; 17:14071-82. [DOI: 10.1039/c5cp01438g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The neural network iterative diagonalization structure for computing the eigenstates of complex symmetric or Hermitian matrices.
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Affiliation(s)
- Hua-Gen Yu
- Department of Chemistry
- Brookhaven National Laboratory
- Upton
- USA
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9
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Ulenikov ON, Bekhtereva ES, Albert S, Bauerecker S, Niederer HM, Quack M. Survey of the high resolution infrared spectrum of methane (12CH4and13CH4): Partial vibrational assignment extended towards 12 000 cm−1. J Chem Phys 2014; 141:234302. [DOI: 10.1063/1.4899263] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- O. N. Ulenikov
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
- Institute of Physics and Technology National Research, Tomsk Polytechnic University, Tomsk 634050, Russia
| | - E. S. Bekhtereva
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
- Institute of Physics and Technology National Research, Tomsk Polytechnic University, Tomsk 634050, Russia
| | - S. Albert
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
- Swiss Light Source, Paul-Scherrer-Institute, CH-5232 Villigen, Switzerland
| | - S. Bauerecker
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
- Institut für Physikalische und Theoretische Chemie, Technische Universität Braunschweig, D-38106 Braunschweig, Germany
| | - H. M. Niederer
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - M. Quack
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
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Nikitin AV, Boudon V, Wenger C, Albert S, Brown LR, Bauerecker S, Quack M. High resolution spectroscopy and the first global analysis of the Tetradecad region of methane 12CH4. Phys Chem Chem Phys 2013; 15:10071-93. [DOI: 10.1039/c3cp50799h] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Amyay B, Fayt A, Herman M. Accurate partition function for acetylene,12C2H2, and related thermodynamical quantities. J Chem Phys 2011; 135:234305. [DOI: 10.1063/1.3664626] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Rotational and vibrational energy levels of methane calculated from a new potential energy surface. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2010.11.008] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Votava O, Masát M, Pracna P, Kassi S, Campargue A. Accurate determination of low state rotational quantum numbers (J < 4) from planar-jet and liquid nitrogen cell absorption spectra of methane near 1.4 micron. Phys Chem Chem Phys 2010; 12:3145-55. [PMID: 20237703 DOI: 10.1039/b922109c] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
An improved procedure for accurate determination of empirical lower state rotational quantum numbers from molecular absorption spectra is demonstrated for methane. We combine the high resolution absorption spectra in the 7070-7300 cm(-1) frequency range obtained in liquid nitrogen cooled cryogenic cell (T = 81 K) and in supersonic planar jet expansion (T(R) = 25 K). Empirical lower state energies of 59 transitions are determined from the ratio of the absolute absorption line strengths at 25 and 81 K. The procedure relies on the realistic description of rotational state populations in the supersonic jet expansion where non-equilibrium nuclear spin isomer distributions are generated due to the rapid cooling. The accuracy of the experimental determination of the lower state energies with J < or = 3 is found to considerably improve the results of the same approach applied to spectra at 296 and 81 K. The 59 transitions with determined lower J values provide a good starting point for the theoretical interpretation of the highly congested icosad region of methane. In particular, the centres of nine vibrational bands are estimated from the transitions with J = 0 lower state rotational quantum number.
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Affiliation(s)
- Ondrej Votava
- J. Heyrovský Institute of Physical Chemistry, ASCR, Dolejskova 3, Prague 8, Czech Republic.
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14
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Mátyus E, Šimunek J, Császár AG. On the variational computation of a large number of vibrational energy levels and wave functions for medium-sized molecules. J Chem Phys 2009; 131:074106. [DOI: 10.1063/1.3187528] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Herman M, Didriche† K, Hurtmans D, Kizil B, Macko P, Rizopoulos A, Poucke PV. FANTASIO: a versatile experimental set-up to investigate jet-cooled molecules. Mol Phys 2007. [DOI: 10.1080/00268970601063820] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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16
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Oyanagi C, Yagi K, Taketsugu T, Hirao K. Highly accurate potential-energy and dipole moment surfaces for vibrational state calculations of methane. J Chem Phys 2006; 124:64311. [PMID: 16483211 DOI: 10.1063/1.2162891] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Full-dimensional ab initio potential-energy surface (PES) and dipole moment surface are constructed for a methane molecule at the CCSD(T)/cc-pVTZ and MP2/cc-pVTZ levels of theory, respectively, by the modified Shepard interpolation method based on the fourth-order Taylor expansion [MSI(4th)]. The reference points for the interpolation have been set in the coupling region of CH symmetric and antisymmetric stretching modes so as to reproduce the vibrational energy levels related to CH stretching vibrations. The vibrational configuration-interaction calculations have been performed to obtain the energy levels and the absorption intensities up to 9000 cm(-1) with the use of MSI(4th)-PES. The calculated fundamental frequencies and low-lying vibrational energy levels show that MSI(4th) is superior to the widely employed quartic force field, giving a better agreement with the experimental values. The absorption bands of overtones as well as combination bands, which are caused by purely anharmonic effects, have been obtained up to 9000 cm(-1). Strongly coupled states with visible intensity have been found in the 6500-9000 cm(-1) region where the experimental data are still lacking.
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Affiliation(s)
- Chikako Oyanagi
- Department of Chemistry, Ochanomizu University, Tokyo, Japan
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17
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18
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Yu HG. Converged quantum dynamics calculations of vibrational energies of CH4 and CH3D using an ab initio potential. J Chem Phys 2004; 121:6334-40. [PMID: 15446929 DOI: 10.1063/1.1789133] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Exact variational calculations of vibrational energies of CH4 and CH3D are carried out using a two-layer Lanczos algorithm based on the ab initio potential energy surface of D. W. Schwenke and H. Partridge, Spectrochim. Acta, Part A 57, 887 (2001). The convergence of the calculated vibrational energies is discussed in detail. In addition, we report all well converged vibrational energy levels up to 6600 cm(-1) for CH4, and those up to 5000 cm(-1) for CH3D, respectively. These results clearly outperform previous theoretical calculations. And a comparison with experimental results available is also made.
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Affiliation(s)
- Hua-Gen Yu
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973-5000, USA.
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19
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Wang XG, Carrington T. A contracted basis-Lanczos calculation of vibrational levels of methane: Solving the Schrödinger equation in nine dimensions. J Chem Phys 2003. [DOI: 10.1063/1.1574016] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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20
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Boursier C, Ménard J, Doyennette L, Menard-Bourcin F. Rovibrational Relaxation of Methane in CH4−N2 Mixtures: Time-Resolved IR−IR Double-Resonance Measurements at 193 K and Kinetic Modeling. J Phys Chem A 2003. [DOI: 10.1021/jp034265m] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Corinne Boursier
- Laboratoire de Physique Moléculaire et Applications, CNRS, Université Pierre et Marie Curie, Tour 13−Bte 76, 4 place Jussieu, 75252 Paris Cedex 05, France
| | - Joseph Ménard
- Laboratoire de Physique Moléculaire et Applications, CNRS, Université Pierre et Marie Curie, Tour 13−Bte 76, 4 place Jussieu, 75252 Paris Cedex 05, France
| | - Lucien Doyennette
- Laboratoire de Physique Moléculaire et Applications, CNRS, Université Pierre et Marie Curie, Tour 13−Bte 76, 4 place Jussieu, 75252 Paris Cedex 05, France
| | - Françoise Menard-Bourcin
- Laboratoire de Physique Moléculaire et Applications, CNRS, Université Pierre et Marie Curie, Tour 13−Bte 76, 4 place Jussieu, 75252 Paris Cedex 05, France
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21
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He SG, Liu AW, Lin H, Hu SM, Zheng JJ, Hao LY, Zhu QS. Study of the stretching vibrational band intensities of XH4 molecules employing four-dimensionalab initio(X=C and Sn) andeffective(X=C and Si) dipole moment surfaces. J Chem Phys 2002. [DOI: 10.1063/1.1520130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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22
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GEORGES R, BONNAMY A, BENIDAR A, DECROI M, BOISSOLES J. FTIR free-jet set-up for the high resolution spectroscopic investigation of condensable species. Mol Phys 2002. [DOI: 10.1080/00268970110117980] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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23
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Hippler M, Quack M. High-resolution Fourier transform infrared and cw-diode laser cavity ringdown spectroscopy of the ν2+2ν3 band of methane near 7510 cm−1 in slit jet expansions and at room temperature. J Chem Phys 2002. [DOI: 10.1063/1.1433505] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Menard-Bourcin F, Boursier C, Doyennette L, Menard J. Rovibrational Energy Transfer in Methane Excited to 2ν3 in CH4−N2 Mixtures from Double-Resonance Measurements. J Phys Chem A 2001. [DOI: 10.1021/jp011712u] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- F. Menard-Bourcin
- Laboratoire de Physique Moléculaire et Applications, CNRS, Université Pierre et Marie Curie, Tour 13 - Bte 76, 4, place Jussieu, 75252 Paris Cedex 05, France
| | - C. Boursier
- Laboratoire de Physique Moléculaire et Applications, CNRS, Université Pierre et Marie Curie, Tour 13 - Bte 76, 4, place Jussieu, 75252 Paris Cedex 05, France
| | - L. Doyennette
- Laboratoire de Physique Moléculaire et Applications, CNRS, Université Pierre et Marie Curie, Tour 13 - Bte 76, 4, place Jussieu, 75252 Paris Cedex 05, France
| | - J. Menard
- Laboratoire de Physique Moléculaire et Applications, CNRS, Université Pierre et Marie Curie, Tour 13 - Bte 76, 4, place Jussieu, 75252 Paris Cedex 05, France
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Hilico JC, Robert O, Loëte M, Toumi S, Pine AS, Brown LR. Analysis of the Interacting Octad System of (12)CH(4). JOURNAL OF MOLECULAR SPECTROSCOPY 2001; 208:1-13. [PMID: 11437546 DOI: 10.1006/jmsp.2001.8364] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The octad system of methane (12)CH(4) has been analyzed with a fourth-order (459 parameters) Hamiltonian for energy levels and a third-order (28 parameters) dipole moment expansion for infrared intensities. Nearly 8000 assigned positions and 2500 measured line intensities (obtained with the Fourier transform spectrometer located at Kitt Peak National Observatory/National Solar Observatory) have been considered in the modeling. Infrared (Octad-Ground State) and hot bands (Octad-Dyad) data have been used. While the model does not reproduce the measurements at their inherent experimental precisions, it has been sufficient to interpret and substantially assign this spectral region of methane for the first time in over 30 years of investigation. Copyright 2001 Academic Press.
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Affiliation(s)
- J.-C. Hilico
- Laboratoire de Physique, le l'Université de Bourgogne, 9 av. A. Savary, Dijon cedex, F-21078, France
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26
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Benidar A, Georges R, Boissoles J, Hamon S, Canosa A, Rowe BR. Uniform Supersonic Expansion for FTIR Absorption Spectroscopy: The nu(5) Band of (NO)(2) at 26 K. JOURNAL OF MOLECULAR SPECTROSCOPY 2000; 199:92-99. [PMID: 10712875 DOI: 10.1006/jmsp.1999.7986] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A high-resolution Fourier transform interferometer (Bruker IFS 120 HR) was combined with a uniform supersonic expansion produced by means of axisymmetric Laval nozzles. The geometry profile of the nozzle enabled us to work under precise thermodynamic and kinetic conditions. The effect of the cooling rate of different nozzles on cluster nucleation is illustrated. The experimental sensitivity was tested by recording the nu(5) band of (NO)(2) at 26 K. Copyright 2000 Academic Press.
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Affiliation(s)
- A Benidar
- Equipe de Spectroscopie Infrarouge, Equipe d'Astrochimie Expérimentale, Laboratoire PALMS, UMR 6627 CNRS-Université de Rennes I, Campus de Beaulieu, Rennes, 35042, France
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27
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Hippler M, Quack M. Cw cavity ring-down infrared absorption spectroscopy in pulsed supersonic jets: nitrous oxide and methane. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(99)01071-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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28
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Abstract
▪ Abstract Except for ortho- and para-H2, little is known about nuclear spin isomers (or spin modifications) of molecules. The main reason is the lack of practical enrichment techniques. Recently, a few enrichment methods were developed, which opened up new possibilities in the field. These methods are briefly reviewed. Substantial progress in the field has been made by the introduction of light-induced drift as a gas-phase separation tool. This is illustrated by extensive data on CH3F, which reveal that the gas-phase ortho-para conversion is governed by intramolecular mixing of the nuclear spin states. The role of direct ortho-para transitions is small. Various aspects of the conversion were investigated in detail: pressure and collision partner dependence, isotope effect, and temperature dependence. The most decisive information on the spin conversion mechanism is derived from the observation of level-crossing resonances in an electric field and the quantum Zeno effect induced by collisions.
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Affiliation(s)
- P L Chapovsky
- Institute of Automation and Electrometry, Russian Academy of Sciences, 630090 Novosibirsk, Russia.
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29
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Carter S, Bowman JM. Variational Calculations of Rotational−Vibrational Energies of CH4 and Isotopomers Using an Adjusted ab Initio Potential. J Phys Chem A 1999. [DOI: 10.1021/jp991723b] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Stuart Carter
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322
| | - Joel M. Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322
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30
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Wang XG, Sibert EL. A nine-dimensional perturbative treatment of the vibrations of methane and its isotopomers. J Chem Phys 1999. [DOI: 10.1063/1.480271] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Carter S, Shnider HM, Bowman JM. Variational calculations of rovibrational energies of CH4 and isotopomers in full dimensionality using an ab initio potential. J Chem Phys 1999. [DOI: 10.1063/1.478750] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Venuti E, Halonen L, Della Valle RG. High dimensional anharmonic potential energy surfaces: The case of methane. J Chem Phys 1999. [DOI: 10.1063/1.478635] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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