The near-IR spectrum of CH3D

Lehmann, Kevin

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https://hdl.handle.net/2142/91472 Copy

Description

Title

The near-IR spectrum of CH3D

Author(s)

Lehmann, Kevin

Contributor(s)

• Tyuterev, Vladimir
• Nikitin, Andrei V.
• Rey, Michael
• Bernath, Peter F.
• Hargreaves, Robert J.
• Yang, Shaoyue

Issue Date

2016-06-20

Keyword(s)

Spectroscopy in Atmospheric Chemistry

Abstract

The near-IR spectrum, from 5000-8960 cm$^{-1}$, of isotopically pure CH$_3$D was taken at temperatures of 294, 400, 500, 600, 700, 800, and 900K with a high resolution Fourier Transform machine at Old Dominion University. The spectra where analyzed to give the wavenumbers, integrated line intensities, and lower state term values (using lines observed in at least 3 different spectra). For the 294 K spectrum 12080 lines with S between 3.6x10$^{-22}$ and 1x10$^{-27}$ cm (not corrected for CH$_3$D natural abundance) were determined for this spectral interval. A theoretical spectrum of CH$_3$D has also been calculated at the Univ. of Reins, with >400,000 transitions predicted between 5000-6300 cm$^{-1}$ with S values between 2.1x10$^{-22}$ and 1 x 10$^{-27}$ cm at 294K. Comparison of the predictions with 175 J” = 0 and 1 transitions previously assigned by the ETH group$^1$ shows that for 130 of these the absolute difference between the observed and predicted line wavenumbers is less than 0.1 cm$^{-1}$ and for all but one transition the absolute difference is less than 1 cm$^{-1}$. In this project, we are combining the temperature dependence of the line intensities, combination differences, and comparisons of line positions and strengths with the theoretical spectrum to extend the assignments of CH$_3$D lines in this spectral region. Selected assignments will be confirmed by IR-IR double resonance measurements at the University of Virginia. Ultimately, we hope to give a global analysis of CH$_3$D spectrum using a global effective Hamiltonian model. \newline 1. Ulenikov, O.N. {\it et al.}, Molecular Physics {\bf 108}, 1209-1240 (2010)

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

En

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http://hdl.handle.net/2142/91472

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Copyright 2016 by the authors

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