Pure rotational as well as rovibrational data of several isotopic species of NeH⁺ have been fit simultaneously.
Several pure rotational transition frequencies were reported in
(1) F. Matsushima, Y. Ohtaki, O. Torige, and K. Takagi, 1998, J. Chem. Phys., 109, 2242.
These data could not be reproduced within the reported experimental uncertainties. As in (1), the transitions of ²²NeH⁺ deviated most with respect to the uncertainties. Trial fits showed that the omission of the two higher-J transitions of this species gave a rather satisfactory fit.
An additional high-J line was published by
(2) D. J. Liu, W. C. Ho, and T. Oka, 1987, J. Chem. Phys. 87, 2442.
Rovibrational transitions of NeH⁺ were recorded by
(3) M. Wong, P. Bernath, and T. Amano, 1982, J. Chem. Phys. 77, 693;
(4) R. S. Ram, P. F. Bernath, and J. W. Brault, 1985, J. Mol. Spectrosc. 113, 451;
and by
(5) S. Civis, J. Sebera, V. Spirko, J. Fiser, W. P. Kraemer, and K. Kawaguchi, 2004, J. Mol. Struct. 695–696, 5.
Some transitions from (4) and (5) were omitted from the fits because of large and irregular residuals. Moreover, the vibrational expansion of the Dunham-type expansion requires many higher order terms; a direct potential fit probably would have been advantageous. Thus, the very weak v = 4 – 3 transitions from (5) were also not included in the fit.
The amount of ion drift effects on the reported frequencies are difficults to estimate. Thus, all predictions should be viewed with some caution, in particular those above 10 THz.
Experimental transitions frequencies with uncertainties larger than 300 kHz have not been merged.
The ab initio dipole moment was assumed to agree with that of the parent species, see e021501.cat.
The partition function takes into account all vibrational states used in the fit. Non-zero contributions of individual vibrational states to the partition function are given in parentheses.