Using CMDS to study spectral shapes of methane broadened by nitrogen and comparison with experiment

Tuong Le Cong, Jose-Luis Domenech, Muriel Lepere, Ha Tran

Research output: Contribution to conferencePoster

Abstract

Absorption spectra of methane transitions broadened by nitrogen have been calculated for the first time using a requantized classical molecular dynamic simulation [1]. For that, the time evolution of the auto-correlation function of the dipole moment vector, assumed along a C-H axis, was computed using accurate site-site intermolecular potentials for a CH4-N2 system [2-4]. A requantization procedure [5] was applied to the classical rotation and spectra were then derived as the Fourier-Laplace transform of the auto-correlation function. These computed spectra were compared with experimental ones recorded with a tunable diode laser spectrometer [6] and a difference-frequency laser one [7]. Specifically, nine isolated methane lines broadened by nitrogen, belonging to various vibrational bands and having rotational quantum numbers J from 0 to 9, were measured at room temperature and at several pressures from 20 to 945 mbar. Comparisons between measured and calculated spectra were made through their fits using the Voigt profile. The results show that ab initio calculated spectra reproduce with very high fidelity non-Voigt effects on the measurements and that classical molecular dynamic simulations can be used to predict spectral shapes of isolated lines of methane perturbed by nitrogen [8]
Original languageEnglish
Publication statusPublished - 22 Aug 2017
EventThe 25th colloquium on High-Resolution Molecular Spectroscopy - University of Helsinki, Helsinki, Finland
Duration: 20 Aug 201725 Aug 2017
http://www.helsinki.fi/kemia/HRMS2017/

Conference

ConferenceThe 25th colloquium on High-Resolution Molecular Spectroscopy
Abbreviated titleHRMS 2017
CountryFinland
CityHelsinki
Period20/08/1725/08/17
Internet address

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methane
nitrogen
autocorrelation
molecular dynamics
laser spectrometers
quantum numbers
dipole moments
simulation
diodes
absorption spectra
room temperature
profiles
lasers

Cite this

Le Cong, T., Domenech, J-L., Lepere, M., & Tran, H. (2017). Using CMDS to study spectral shapes of methane broadened by nitrogen and comparison with experiment. Poster session presented at The 25th colloquium on High-Resolution Molecular Spectroscopy, Helsinki, Finland.
Le Cong, Tuong ; Domenech, Jose-Luis ; Lepere, Muriel ; Tran, Ha. / Using CMDS to study spectral shapes of methane broadened by nitrogen and comparison with experiment. Poster session presented at The 25th colloquium on High-Resolution Molecular Spectroscopy, Helsinki, Finland.
@conference{0a37915e3dbc49b7ad5f960f2bd11fb8,
title = "Using CMDS to study spectral shapes of methane broadened by nitrogen and comparison with experiment",
abstract = "Absorption spectra of methane transitions broadened by nitrogen have been calculated for the first time using a requantized classical molecular dynamic simulation [1]. For that, the time evolution of the auto-correlation function of the dipole moment vector, assumed along a C-H axis, was computed using accurate site-site intermolecular potentials for a CH4-N2 system [2-4]. A requantization procedure [5] was applied to the classical rotation and spectra were then derived as the Fourier-Laplace transform of the auto-correlation function. These computed spectra were compared with experimental ones recorded with a tunable diode laser spectrometer [6] and a difference-frequency laser one [7]. Specifically, nine isolated methane lines broadened by nitrogen, belonging to various vibrational bands and having rotational quantum numbers J from 0 to 9, were measured at room temperature and at several pressures from 20 to 945 mbar. Comparisons between measured and calculated spectra were made through their fits using the Voigt profile. The results show that ab initio calculated spectra reproduce with very high fidelity non-Voigt effects on the measurements and that classical molecular dynamic simulations can be used to predict spectral shapes of isolated lines of methane perturbed by nitrogen [8]",
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day = "22",
language = "English",
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Le Cong, T, Domenech, J-L, Lepere, M & Tran, H 2017, 'Using CMDS to study spectral shapes of methane broadened by nitrogen and comparison with experiment' The 25th colloquium on High-Resolution Molecular Spectroscopy, Helsinki, Finland, 20/08/17 - 25/08/17, .

Using CMDS to study spectral shapes of methane broadened by nitrogen and comparison with experiment. / Le Cong, Tuong; Domenech, Jose-Luis; Lepere, Muriel; Tran, Ha.

2017. Poster session presented at The 25th colloquium on High-Resolution Molecular Spectroscopy, Helsinki, Finland.

Research output: Contribution to conferencePoster

TY - CONF

T1 - Using CMDS to study spectral shapes of methane broadened by nitrogen and comparison with experiment

AU - Le Cong, Tuong

AU - Domenech, Jose-Luis

AU - Lepere, Muriel

AU - Tran, Ha

PY - 2017/8/22

Y1 - 2017/8/22

N2 - Absorption spectra of methane transitions broadened by nitrogen have been calculated for the first time using a requantized classical molecular dynamic simulation [1]. For that, the time evolution of the auto-correlation function of the dipole moment vector, assumed along a C-H axis, was computed using accurate site-site intermolecular potentials for a CH4-N2 system [2-4]. A requantization procedure [5] was applied to the classical rotation and spectra were then derived as the Fourier-Laplace transform of the auto-correlation function. These computed spectra were compared with experimental ones recorded with a tunable diode laser spectrometer [6] and a difference-frequency laser one [7]. Specifically, nine isolated methane lines broadened by nitrogen, belonging to various vibrational bands and having rotational quantum numbers J from 0 to 9, were measured at room temperature and at several pressures from 20 to 945 mbar. Comparisons between measured and calculated spectra were made through their fits using the Voigt profile. The results show that ab initio calculated spectra reproduce with very high fidelity non-Voigt effects on the measurements and that classical molecular dynamic simulations can be used to predict spectral shapes of isolated lines of methane perturbed by nitrogen [8]

AB - Absorption spectra of methane transitions broadened by nitrogen have been calculated for the first time using a requantized classical molecular dynamic simulation [1]. For that, the time evolution of the auto-correlation function of the dipole moment vector, assumed along a C-H axis, was computed using accurate site-site intermolecular potentials for a CH4-N2 system [2-4]. A requantization procedure [5] was applied to the classical rotation and spectra were then derived as the Fourier-Laplace transform of the auto-correlation function. These computed spectra were compared with experimental ones recorded with a tunable diode laser spectrometer [6] and a difference-frequency laser one [7]. Specifically, nine isolated methane lines broadened by nitrogen, belonging to various vibrational bands and having rotational quantum numbers J from 0 to 9, were measured at room temperature and at several pressures from 20 to 945 mbar. Comparisons between measured and calculated spectra were made through their fits using the Voigt profile. The results show that ab initio calculated spectra reproduce with very high fidelity non-Voigt effects on the measurements and that classical molecular dynamic simulations can be used to predict spectral shapes of isolated lines of methane perturbed by nitrogen [8]

M3 - Poster

ER -

Le Cong T, Domenech J-L, Lepere M, Tran H. Using CMDS to study spectral shapes of methane broadened by nitrogen and comparison with experiment. 2017. Poster session presented at The 25th colloquium on High-Resolution Molecular Spectroscopy, Helsinki, Finland.