Magnesium monohydroxide, X 2Σ+
Species tag 041508
Date of EntryNov. 2013
ContributorH. S. P. Müller

The experimental data were taken from
(1) W. L. Barclay Jr., and M. A. Anderson, L. M. Ziurys, 1992, Chem. Phys. Lett. 196, 225.
The N = 3 – 2 transition frequencies, which showed some broadening, possibly because of hyperfine splitting caused by the H nucleus, were omitted from the fit because of large residuals both with the splitting as well as without the splitting (using the intensity-weighted averages). Information on the hyperfine structure is available from ESR measurement of MgO in neon matrix and from quantum chemical calculations. These were reported by
(2) J. M. Brom, Jr., and W. Weltner, Jr., 1973, J. Chem. Phys. 58, 5322;
and by
(3) B. Fernández, 1996, Chem. Phys. Lett. 259, 635; respectively.
A separate prediction considering 1H hyperfine splitting with J" ≤ 4 is available together with appropriate partition function values.
The predictions with hyperfine structure should be viewed with considerable caution. In contrast, the hyerfine free predictions should be sufficiently accurate for radio astronomical observations throughout.
The dipole was assumed to be slightly smaller than that of CaOH (

Lines Listed78
Frequency / GHz< 1000
Max. J33
log STR0-5.3
log STR1-4.5
Isotope Corr.-0.1035
Egy / cm–10.0
 µa / D1.4
 µb / D 
 µc / D 
 A / MHz 
 B / MHz14822.52
 C / MHz 
detected in ISM/CSMno

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