Maki A.,15012 24th Ave. S.E |
Price J.E.,Oregon State University |
Harzan J.,Oregon State University |
Nibler J.W.,Oregon State University |
And 3 more authors.
Journal of Molecular Spectroscopy | Year: 2015
The high-resolution infrared absorption spectrum of spiropentane (C5H8) has been measured from 200 to 4000 cm-1, and a detailed analysis is presented for eight bands in the region from 700 to 2200 cm-1. Two fundamental perpendicular bands were analyzed, ν22 and ν24 near 1050 and 780 cm-1, respectively, along with two fundamental parallel bands, ν14 and ν16 near 1540 and 990 cm-1, respectively. Two other fundamentals, ν17 and ν23, are seen as intense overlapping bands near 880 cm-1 and are Coriolis-coupled, producing a complex mixture in which only P-branch transitions could be tentatively assigned for ν17. In addition, three binary combination bands were fit at about 1570, 2082, and 2098 cm-1 which are assigned as either 2ν24 or ν5 + ν16 in the first case, ν4 + ν22 in the second case, and 2ν22 in the latter case. The two l-type resonance constants, q+ and q-, were determined for each of the two perpendicular fundamentals ν22 and ν24. Those two constants were also responsible for splittings observed in the K = 3 levels of ν24. For the ground state the order of the split K = 2 B1/B2 levels has been reversed from that reported previously, based on the measurements and assignments for the ν24 band. Rovibrational parameters deduced from the analyses are compared with those obtained from density functional Gaussian calculations at the anharmonic level. © 2015 Published by Elsevier Inc.
Jacquinet-Husson N.,University Pierre and Marie Curie |
Crepeau L.,University Pierre and Marie Curie |
Armante R.,University Pierre and Marie Curie |
Boutammine C.,University Pierre and Marie Curie |
And 55 more authors.
Journal of Quantitative Spectroscopy and Radiative Transfer | Year: 2011
The updated 2009 edition of the spectroscopic database GEISA (Gestion et Etude des Informations Spectroscopiques Atmosphériques; Management and Study of Atmospheric Spectroscopic Information) is described in this paper. GEISA is a computer-accessible system comprising three independent sub-databases devoted, respectively, to: line parameters, infrared and ultraviolet/visible absorption cross-sections, microphysical and optical properties of atmospheric aerosols. In this edition, 50 molecules are involved in the line parameters sub-database, including 111 isotopologues, for a total of 3,807,997 entries, in the spectral range from 10-6 to 35,877.031cm-1.The successful performances of the new generation of hyperspectral sounders depend ultimately on the accuracy to which the spectroscopic parameters of the optically active atmospheric gases are known, since they constitute an essential input to the forward radiative transfer models that are used to interpret their observations. Currently, GEISA is involved in activities related to the assessment of the capabilities of IASI (Infrared Atmospheric Sounding Interferometer; http://smsc.cnes.fr/IASI/index.htm) on board the METOP European satellite through the GEISA/IASI database derived from GEISA. Since the Metop-A (http://www.eumetsat.int) launch (19 October 2006), GEISA is the reference spectroscopic database for the validation of the level-1 IASI data. Also, GEISA is involved in planetary research, i.e., modeling of Titan's atmosphere, in the comparison with observations performed by Voyager, or by ground-based telescopes, and by the instruments on board the Cassini-Huygens mission.GEISA, continuously developed and maintained at LMD (Laboratoire de Météorologie Dynamique, France) since 1976, is implemented on the IPSL/CNRS (France) "Ether" Products and Services Centre WEB site (http://ether.ipsl.jussieu.fr), where all archived spectroscopic data can be handled through general and user friendly associated management software facilities. More than 350 researchers are registered for on line use of GEISA. © 2011 Elsevier Ltd.
Maki A.G.,15012 24th Ave. S.E.
Journal of Molecular Spectroscopy | Year: 2012
High-resolution spectra of two monoisotopically substituted and two triisotopically substituted species of cyanogen have been measured from 490 to 3000 cm -1. A total of 19 vibrational states for 14N 13C 12C 14N, 12 vibrational states for 15N 13C 12C 15N, 17 vibrational states for 15N 12C 12C 14N, and 5 vibrational states for 15N 13C 13C 14N were measured, most for the first time. The ν 1 bands, which are allowed for these C ∞v molecules, were observed and their relative intensities were measured and compared with ab initio calculations. The ν 1 transitions of 14N 13C 12C 14N were 47 times weaker than those of ν 3 and the ν 1 transitions of 15N 12C 12C 14N were even weaker by a factor of 4.1. Other C ∞v allowed transitions, ν 4 and ν 3 + ν 5, were also observed and their intensities were compared to the intensities of transitions allowed under the D ∞h selection rules that apply to the most abundant cyanogen molecule, 14N 12C 12C 14N. © 2012 Elsevier B.V. All rights reserved.
Maki A.G.,15012 24th Ave. S.E.
Journal of Molecular Spectroscopy | Year: 2011
The high-resolution spectrum of cyanogen (14N12C 12C14N) has been measured from 500 to 4900 cm -1. For this isotopomer many combination levels with both degenerate fundamentals, ν4 and ν5, have been measured for the first time and the effects of vibrational l-type resonance are observed as well as rotational l-type resonance. The effects of the vibrational resonance coupling ν2 and 2ν4 have also been studied. The data have been combined with earlier measurements below 500 cm-1 to give a comprehensive catalog of the vibrational energy levels and the rovibrational constants for the normal isotopomer of cyanogen. A comparison of the term value constants for the three major symmetric isotopomers is given and they are compared with a recent ab initio calculation. The present data were combined with earlier work on the two symmetric isotopomers, 13C 214N2 and 12C215N2, to obtain the equilibrium bond lengths, r CC = 138.109(60) pm and rCN = 115.976(40) pm. © 2011 Elsevier Inc. All rights reserved.
Maki A.G.,15012 24th Ave. S.E.
Journal of Molecular Spectroscopy | Year: 2014
The absorption spectrum of sodium iodide vapor between 200 and 275 cm -1 has been measured with a resolution of 0.006 cm-1 at a temperature of 1096 K. The Δv = 1 transitions from v = 1 ← 0 to v = 13 ← 12 have been measured. Dunham constants are given from an least-squares analysis of 1285 fairly well resolved transitions. The band center for the fundamental band is ν0 = 257.2837 ± 0.0002 cm -1. The relative intensities of the Δv = 1 transitions from different vibrational states are studied and it is shown that the intensity is roughly proportional to v″ + 1 as expected from the harmonic oscillator approximation. From measurements of the Herman-Wallis constant, α1,0 = -0.0054 ± 0.0008, it is estimated that the transition moment must be μ1,0 ≈ 0.135 ± 0.020 debye. © 2014 Elsevier Inc. All rights reserved.