The transition frequencies were published by
(1) H. S. P. Müller, J. K. Jørgensen, J.-C. Guillemin, F. Lewen, and S. Schlemmer, 2023, J. Mol. Spectrosc. 394, Art. No. 111777.
The calculation should be sufficient for all observational purposes. Calculated frequencies with uncertainties exceeding 0.1 MHz should be viewed with some caution.
There are no non-trivial spin-statistics in this molecule, in contrast to the main isotopolog.
The partition function takes into account the ground vibrational state only because the molecule resides in somewhat colder regions. Excited vibrational states are quite high; their effect is still modest at room temperature.
The dipole moment was derived in (1) from that of the main isotopolog published by
(2) G. L. Cunningham Jr., A. W. Boyd, R. J. Myers, W. D. Gwinn, and W. I. Le Van, 1951, J. Chem. Phys. 19, 676 ;
with its value slightly increased by 0.02 D due to an updated reference value for OCS as outlined in
(3) H. S. P. Müller, J. C. Guillemin, F. Lewen, and S. Schlemmer, 2022, J. Mol. Spectrosc. 384, Art. No. 111584.