CH+, v = 2 – 0 band
Methylidynium, v = 2 – 0 IR band
Species tag 013505
Date of EntryMay 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 some caution; considerable caution is advised for transitions beyond J" = 10.
A transition dipole moment value was calculated ab initio by
(8) B. Follmeg, P. Rosmus, and H.-J. Werner, 1987, Chem. Phys. Lett. 136, 562.
The transition dipole moment is by accident very small; it is uncertain if the ab initio calculations are reliable enough in that respect. Moreover, it is not known if the intensities are modeled appropriately by only this transition dipole moment.

Lines Listed27
Frequency / GHz< 166001
Max. J14
log STR0-100.0
log STR1-15.0
Isotope Corr.-0.0
Egy / (cm–1)0.0 / 5362.72
 µa / D0.00017
 µb / D 
 µc / D 
 B417651.6 / 388427
detected in ISM/CSMno

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