CaC2
Calcium dicarbide, X 1A1
Species tag 064528
Version1*
Date of EntryApr. 2025
ContributorH. S. P. Müller

Laboratory and astronomical lines were reported by
(1) H. Gupta, P. B. Changala, J. Cernicharo, J. R. Pardo, M. Agúndez, C. Cabezas, B. Tercero, M. Guélin, and M. C. McCarthy, 2024, Astrophys. J. Lett. 966, Art. No. L28.
P. B. Changala is thanked for providing initial spectroscopic parameters. The quantum number J was limited to 15 because of the limited experimental data. The calculations are sufficient for observations in cold sources and somewhat sufficient in luke warm sources. Transition frequencies with calculated uncertainties exceeding 0.3 MHz should be viewed with some caution.
The dipole moment was taken from a quantum-chemical calculation in (1).

Lines Listed120
Frequency / GHz< 220
Max. J15
log STR0-6.0
log STR1-5.0
Isotope Corr. 
Egy / cm–10.0
 µa / D11.1
 µb / D 
 µc / D 
 A / MHz~52380
 B / MHz7551.4
 C / MHz6582.8
 Q(300.0)8608.7244
 Q(225.0)5588.5176
 Q(150.0)3040.7257
 Q(75.00)1075.1126
 Q(37.50)380.5208
 Q(18.75)134.8921
 Q(9.375)47.9678
 Q(5.000)19.1457
 Q(2.725)8.8001
detected in ISM/CSMyes


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