The experimental frequencies have been reported by
(1) S. Thorwirth, H. S. P. Müller, and G. Winnewisser, 2001, Phys. Chem. Chem. Phys. 3, 1236.
The uncertainties in (1) are probably very conservative. Some parameters were kept fixed to values determined for the main isotopic species.
The state is perturbed by several other states, probably the most by (0021). Predictions may be reliable up to around 350 GHz.
Vibrational contributions to the partition function of HCC¹³CN are also available.
The dipole moment was assumed to agree with that of the main isotopolog, see e051507.cat.