We measure speed-dependent Voigt lineshape parameters with temperature-dependence exponents for several hundred spectroscopic features of pure water spanning 6801-7188 cm. The parameters are extracted from broad bandwidth, high-resolution dual frequency comb absorption spectra with multispectrum fitting techniques. The data encompass 25 spectra ranging from 296 K to 1305 K and 1 to 17 Torr of pure water vapor. We present the extracted parameters, compare them to published data, and present speed-dependence, self-shift, and self-broadening temperature-dependent parameters for the first time. Lineshape data is extracted using a quadratic speed-dependent Voigt profile and a single self-broadening power law temperature-dependence exponent over the entire temperature range. The results represent an important step toward a new high-temperature database using advanced lineshape profiles.
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http://dx.doi.org/10.1016/j.jqsrt.2018.02.025 | DOI Listing |
J Chem Phys
July 2024
Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
This work theoretically studied the spectral line shape of H2O perturbed by Ar in the temperature range of 20-300 K for the pure rotational lines below 360 cm-1, as well as three lines (31, 2 ← 44, 1, 54, 2 ← 41, 3, and 73, 5 ← 60, 6) in the v2 band. In order to perform precise dynamical calculations at low collision energies, a full-dimensional long-range potential energy surface was constructed for the H2O-Ar system for the first time to correct the long range of our newly developed intermolecular potential energy surface. Subsequently, the six line-shape parameters (pressure-broadening and -shifting parameters, their speed dependencies, and the complex Dicke parameters) were determined from the generalized spectroscopic cross section by the full quantum time-independent close-coupling approach on this new potential energy surface.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
May 2024
Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Toruń, Poland. Electronic address:
We present the results of the spectral line-shape study of the first measurement of the extremely weak (7-0) band of the CO molecule. Measurements were done with a highly sensitive cavity ring-down spectrometer. Collisional narrowing, analyzed in terms of speed-dependent effects, was observed for the first time for transitions with line intensities below 2⋅10 cm/molecule at 296 K.
View Article and Find Full Text PDFJ Chem Phys
October 2023
Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
This work studied the rovibrational absorption spectral line-shape parameters of the P(1)-P(10) and R(0)-R(9) lines for Hydrogen fluoride perturbed by argon in the 0-0, 1-0, and 2-0 vibrational bands at 20-1000 K. A dataset of beyond-Voigt line-shape parameters (pressure broadening and shifting parameters, their speed dependencies, and the complex Dicke parameters) has been theoretically determined for the first time from generalized spectroscopic cross-section calculated by the full quantum scattering calculations. Then these parameters were employed to predict the line shape and asymmetry based on the partially-correlated speed-dependent hard-collision and the partially-correlated quadratic-speed-dependent hard-collision profiles.
View Article and Find Full Text PDFProc Biol Sci
May 2023
Department of Biology, Lund University, 223 62 Lund, Sweden.
The efficiency with which flying animals convert metabolic power to mechanical power dictates an individual's flight behaviour and energy requirements. Despite the significance of this parameter, we lack empirical data on conversion efficiency for most species as measurements are notoriously difficult to obtain. Furthermore, conversion efficiency is often assumed to be constant across flight speeds, even though the components driving flight power are speed-dependent.
View Article and Find Full Text PDFJ Quant Spectrosc Radiat Transf
September 2021
Atomic and Molecular Physics Division, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA.
This paper outlines the major updates of the line-shape parameters that were performed for the nitrous oxide (NO) and carbon monoxide (CO) molecules listed in the HITRAN2020 database. We reviewed the collected measurements for the air- and self-broadened NO and CO spectra to determine proper values for the spectroscopic parameters. Careful comparisons of broadening parameters using the Voigt and speed-dependent Voigt line-shape profiles were performed among various published results for both NO and CO.
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