Argonium, 1Σ+, 38Ar isotopic species
Species tag 039511
Date of EntryDec. 2013
ContributorH. S. P. Müller

Pure rotational as well as rovibrational data of several isotopic species of ArH+ have been fit simultaneously.
The rotational spectrum up to J = 7 – 6 was reported by
(1) J. M. Brown, D. A. Jennings, M. Vanek, L. R. Zink, and K. Evenson, 1988, J. Mol. Spectrosc. 128, 587.
The J = 1 – 0 transition frequencies of three ArD+ isotopic species involving 40Ar, 36Ar, and 38Ar, were published by
(2) W. C. Bowman, G. M. Plummer, E. Herbst, and F. C. De Lucia, 1983, J. Chem. Phys. 79, 2093;
the reported uncertainties for the 40Ar and 36Ar species have been increased somewhat.
High-J pure rotational transition frequencies of ArD+ were taken from
(3) H. Odashima, A. Kozato, F. Matsushima, S. Tsunekawa, and K. Takagi, 1999, J. Mol. Spectrosc. 195, 356.
High-J pure rotational transitions of ArH+ up to high vibrational states were detected in the lower infrared region by
(4) D. J. Liu, W. C. Ho, and T. Oka, 1987, J. Chem. Phys. 87, 2442.
Rovibrational transitions of ArH+ were recorded by
(5) J. W. Brault and S. P. Davis, 1982, Physica Scripta 25, 268.
Additional high-v transitions as well as transitions of ArD+ were reported by
(6) J. W. C. Johns, 1984, J. Mol. Spectrosc. 106, 124.
Infrared data for 36ArH+ and 38ArH+ was provided by
(7) R. R. Filueira and C. E. Blom, 1988, J. Mol. Spectrosc. 127, 279.
There is great consistency among essentially all experimental data. Therefore, it may well be that ion drift effects on the reported frequencies are small. Nevertheless, all predictions should be viewed with some caution, especially if the calculated uncertainties exceed 2 MHz by far.
There are no experimental transitions frequencies for 38ArH+; reliable predictions can be derived from the available species.
The second most important intersteller argon isotope is 38Ar. The by far dominant isotope on Earth is 40Ar, but it originates almost entirely from the radioactive decay of 40K. Its relative abundance in the ISM is almost negligible.
The partition function takes into account all vibrational states used in the fit.
The dipole moment was assumed to agree with that of the main species, see e041504.cat.

Lines Listed27
Frequency / GHz< 15226
Max. J27
log STR0-15.0
log STR1-15.0
Isotope Corr.-2.473
Egy / (cm-1)0.0
 µa / D2.177
 µb / D 
 µc / D 
detected in ISM/CSMyes

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