The far-infrared spectrum of hydrogen sulfide. The (000) rotational constants of , , and

Abstract

The pure rotation spectrum of hydrogen sulfide has been recordcd betwcen 50 and 320 c m ' with a Fouricr transform spectrometer at an apodized resolution of 0.005 cnl-'. This high resolution and a good signal-to-noise ratio lcad to a significant improvement in the accuracy of the wavenumbers of thc rotational transitions of the three isotopic specics H;'s, H;'S, and H~S that were observed in natural abundance. Thcse rotational transitions, together with the available microwave data, havc been included in a least squarcs fit lcading to thc determination of precise 1.otational constants for cach isotopic spccies. Finally, these constants have been used to calculate prcciscly the absorption of natural hydragen sulfide in the far-infrarcd region of the spectrum.Le spectre de rotation pure du sulfure d'hydrogenc a Ctt enregistrC sur un spectromttre par transformte de Fourier entre 50 et 320 c m ' avec une risolution apodiste de 0,005 c m ' . Cette haute rCsolution et un trks bon rapport signal sur bruit ont permis d7amCliorer notablement la prCcision des nombres d'ondes des transitions rotationelles des trois especes isotopique H:' s, HI'S, et H;S observies en abondance naturelle. Ccs transitions rotationelles ainsi que les donnCes microondes existantes ont C t t ensuite introduites dans un calcul de moindres carrCs permettant, pour chaque isotope, la determination dc constantes rotationelles prCcises. Enfin, en utilisant ces constantes. il a Cte possiblc de calculer prtcisCmcnt I'absorption du sulfurc d'hydrogene nature1 dans I'infrarouge lointain.

The H2S Spectrum around 0.7 μm

“…The ground state energy levels were taken from Ref. (17), and the initial band centers and rotational and coupling constants were extrapolated from lower-lying states (1,5,18). In this way it turned out that we were able to assign only the lines with K a ϭ 0 quantum numbers.…”

The HITRAN 2004 molecular spectroscopic database

“…while the lower-state energy levels were calculated using the rotational constants of Flaud et al [432] . It appeared that the band center of this band was off by about 0.002 cm −1 in HI-TRAN2012 while some higher-J rotational transitions were off by up to ∼0.055 cm −1 .…”

Least-Squares Mass-Dependence Molecular Structures

“…Here the data for seven isotopomers from Refs. (45)(46)(47) were fitted with the same models. The use of parallel axes gave a marginally better fit ( ϭ 4.9 ϫ 10 Ϫ5 u Å 2 ) than principal axes ( ϭ 5.4 ϫ 10 Ϫ5 u Å 2 ).…”