Experimental data refer to the ²⁷AlF isotopic species. A Born-Oppenheimer breakdown value was estimated for Y₀₁, even though its effect is very small.
Rotational transition frequencies were reported by
(1) F. C. Wyse, W. Gordy, and E. F. Pearson, 1970, J. Chem. Phys. 52, 3887;
and by
(2) J. Hoeft, F. J. Lovas, E. Tiemann, and T. Törring, 1970, Z. Naturforsch. 25a, 1029.
Also used in the model were rovibrational transition frequencies from
(3) A. G. Maki and F. J. Lovas, 1982, J. Mol. Spectrosc. 95, 80;
and from
(4) H. G. Hedderich and P. F. Bernath, 1992, J. Mol. Spectrosc. 153, 73.
The highest-J ground state transition of (1) was omitted because of a large deviation between measured frequency and that calculted from the final spectroscopic parameters.
The calculated transitions should be accurate enough for all observational purposes. Some caution may be advised for those at high J or high v. Al hyperfine splitting may be resolvable at very low J, but these transitions are likely too weak to be observable.
Only the first 5 vibrational states were included in the calculation of partition function values. The values at 1000 K and higher have been estimated.
The dipole moment from a quantum-chemical calculation was assumed to agree with that of the main isotoplog, see e046528.cat.