The 4VOH Absorption Spectrum of HDO

✍ Scribed by Olga Naumenko; Elena Bertseva; Alain Campargue

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 381 KB
• Volume: 197
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1999.7917

✦ Synopsis

The absorption spectrum of HDO was recorded by intracavity laser absorption spectroscopy in the 13 560 -14 050 cm Ϫ1 spectral region. Among 437 lines attributed to HDO, 399 were assigned to the 4 3 highly excited overtone transition. One hundred twenty-nine experimental energy levels were derived from the spectrum identification with rotational quantum numbers J as high as 16 and K a as high as 7. The (004) vibrational state of HDO was found to be nearly isolated. Rotational and centrifugal distortion parameters of the effective rotational Hamiltonian in the Pade-Borel approximants form, retrieved from the fitting, allow the reproduction of the experimental energy levels with the root-mean-square deviation of 0.012 cm Ϫ1 , close to the experimental accuracy. Some rotational energy levels of the ( 004) state seem to be slightly perturbed by local resonances with the (052) highly excited bending state. The resonance mixing was found to be large enough to give rise to seven 5 2 ϩ 2 3 transitions, but otherwise too weak to be observable. The maximum difference between the derived experimental energy levels and the recent high accuracy ab initio predictions (H. Partridge and D. W. Schwenke, J. Chem. Phys. 106, 4618 -4639 (1997)) is Ϫ2.7 cm Ϫ1 .