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Author Surin, L. A. ♦ Schlemmer, S. ♦ Tarabukin, I. V. ♦ Breier, A. A. ♦ Giesen, T. F. ♦ McCarthy, M. C. ♦ Avoird, A. van der
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ AMMONIA ♦ BOUND STATE ♦ COMPUTERIZED SIMULATION ♦ DE-EXCITATION ♦ EXCITATION ♦ FOURIER TRANSFORMATION ♦ GHZ RANGE ♦ HYDROGEN ♦ MICROWAVE RADIATION ♦ MOLECULES ♦ RESOLUTION ♦ SPECTRA ♦ SPECTROMETERS ♦ SPECTROSCOPY ♦ SPIN ♦ SURFACES ♦ VAN DER WAALS FORCES
Abstract We report the first high resolution spectroscopic study of the NH{sub 3}–H{sub 2} van der Waals molecular complex. Three different experimental techniques, a molecular beam Fourier transform microwave spectrometer, a millimeter-wave intracavity jet OROTRON spectrometer, and a submillimeter-wave jet spectrometer with multipass cell, were used to detect pure rotational transitions of NH{sub 3}–H{sub 2} in the wide frequency range from 39 to 230 GHz. Two nuclear spin species, ( o )-NH{sub 3}–( o )-H{sub 2} and ( p )-NH{sub 3}–( o )-H{sub 2}, have been assigned as carriers of the observed lines on the basis of accompanying rovibrational calculations performed using the ab initio intermolecular potential energy surface (PES) of Maret et al. The experimental spectra were compared with the theoretical bound state results, thus providing a critical test of the quality of the NH{sub 3}–H{sub 2} PES, which is a key issue for reliable computations of the collisional excitation and de-excitation of ammonia in the dense interstellar medium.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2017-03-20
Publisher Place United States
Journal Astrophysical Journal
Volume Number 838
Issue Number 1


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