Methylidynium, 1Σ+, 13C isotopolog
Species tag 014502
Date of EntryApr. 2010
ContributorH. S. P. Müller

A combined fit of all available data of all isotopic species has been carried out; details are available in
(1) H. S. P. Müller, 2010, Astron. Astrophys. 514, Art. No. L6.
The J" = 0 transition frequencies of CH+, 13CH+, and CD+, were reported by
(2) T. Amano, 2010, Astrophys. J. 716, L1.
Additional rovibrational transitions between the electronic X and A states of four isotopologs as reported in (1) were also used in the fit. The CH+ data were taken from
(3) A. Carrington and D. A. Ramsay, 1982, Phys. Scr. 25, 272;
and from
(4) R. Hakalla, R. Kepa, W. Szajna, and M. Zachwieja, 2006, Eur. Phys. J. D 38, 481.
13CH+, CD+, and 13CD+ data were taken from
(5) Z. Bembenek, 1997, J. Mol. Spectrosc. 181, 136;
(6) Z. Bembenek, H. Cisak, R. Kepa, 1987, J. Phys. B 20, 6197;
and from
(7) Z. Bembenek, 1997, J. Mol. Spectrosc. 182, 439;
Predictions should be viewed with considerable caution for transitions beyond J" = 10.
The hyperfine splitting caused by the 13C nucleus may be relevant in quiescent sources for low values of J. Therefore, a separate hyperfine calculation is provided for J" up to 2. The pqartition function has to be multiplied with 2 if hyperfine splitting is taken into account.
A dipole moment value was estimated based on ab initio calculation for CH+ and CD+ by
(8) B. Follmeg, P. Rosmus, and H.-J. Werner, 1987, Chem. Phys. Lett. 136, 562.

Lines Listed18
Frequency / GHz< 14034
Max. J18
log STR0-9.0
log STR1-9.0
Isotope Corr.-1.971
Egy / (cm–1)0.0
 µa / D1.7
 µb / D 
 µc / D 
detected in ISM/CSMyes

Database maintained by Holger S. P. Müller and Sven Thorwirth, programming by D. Roth and F. Schloeder