The observed transitions were taken from
(1) E. F. Pearson, B. P. Winnewisser, and M. B. Trueblood, 1976, Z. Naturforsch. 31a, 1259;
from
(2) P. Kuipers, T. Törring, and A. Dymanus, 1975, Z. Naturforsch. 30a, 1256;
from
(3) T. T. Raw, T. Yamamura, C. W. Gillies, 1987, J. Chem. Phys. 87, 3706;
and from
(4) Y. Kawashima, R. D. Suenram, and E. Hirota, 1996, J. Mol. Spectrosc. 175, 99.
The predictions should be reliable up to 350 GHz.
At low values of J, ³⁹K hyperfine splitting is resolvable. Therefore, a separate prediction considering ³⁹K hyperfine splitting with J" ≤ 4 is available. Note: The partition function does not include the spin-multiplicities of ³⁹K ! Therefore, partition function values have to be multiplied by 4 when considering ³⁹K hyperfine splitting !
The dipole moment was taken from
(5) J. Cederberg, D. Olson, D. Rioux, T. Dillemuth, B. Borovsky, J. Larson, S. Cheah, M. Carlson, and M. Stohler, 1996, J. Chem. Phys. 105, 3361.