The experimental transition frequencies were taken from
(1) C. W. Chou, A. L. Collopy, C. Kurz, Y. Lin, M. E. Harding, P. N. Plessow, T. Fortier, S. Diddams, D. Leibfried, D. R. Leibrandt, 2020, Science 367, 1458.
The octic distortion parameter was not determined significantly and was kept fixed to the quantum-chemically calculated value.
The calculations are sufficient for observational purposes. Transitions with calculated uncertainies exceeding 0.2 MHz should be viewed with caution.
The dipole moment was calculated quantum-chemically from
(2) M. Abe, M. Kajita, M. Hada, and Y. Moriwaki, 2010, J. Phys. B 43, Art. No. 245102.