Comparison of rotational relaxation rate laws to characterize the Raman Q-branch spectrum of CO at 295 K

J. P. Looney, G. J. Rosasco, L. A. Rahn, W. S. Hurst, J. W. Hahn

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We test the ability of the energy corrected sudden (ECS), modified exponential gap (MEG) and the statistical power-exponential gap (SPEG) rate laws to characterize line broadening and line interference in the CO Q-branch at 295 K. All three rate laws fit the experimental linewidth data. The ECS law is found to predict too much spectral collapse. The MEG and SPEG laws both adequately model spectral collapse, but with different implications about the role of dipolar and quadrupolar symmetry forces in CO:CO line broadening. From semiclassical calculations of CO linewidths, we conclude that the SPEG law with a restriction to even ΔJ changes is the more physically correct model.

Original languageEnglish
Pages (from-to)232-238
Number of pages7
JournalChemical Physics Letters
Issue number3
Publication statusPublished - 1989 Sep 15


All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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