The data set has been extended with respect to the first entry of Oct. 2005. Laboratory data up to 551 GHz were taken from
(1) P. Caselli and L. Dore, 2005, Astron. Astrophys., 433, 1145.
Additional data beyond 1 THz were recently published by
(2) L. Bizzocchi, F. Tonolo, B. M. Giuliano, P. Caselli, M. Melosso, L. Dore, S. Alessandrini, C. Puzzarini, and A. Pietropolli Charmet, 2024, Astrophys. J., 970, Art. No. 26.
The uncertainties in the present calculation are the ones implicitely used in (1) and (2), not the ones stated. The calculation should be sufficiently accurate for observational purposes. Increasing caution is advised above 2 THz.
At low J, it is possible to resolve the D hyperfine splitting. Therefore, a separate hyperfine calculation up to J" = 2 is provided. The hyperfine parameters were taken from the DCO⁺ isotopolog, tag 030510. Note: The partion function given below takes into account this splitting! In addition, it refers to the ground vibrational state only; an estimate of the vibrational partition function of HCO⁺ may be applied.
The dipole moment is assumed to agree with that of the main isotopic species, see e029507.cat.