NaK bound–free and bound–bound 4 3Σ + → a 3Σ + emission

• Published in: Journal of molecular spectroscopy 2011-02, Vol.265 (2), p.74-80
• Main Authors: McGeehan, B.M., Ashman, S., Wolfe, C.M., Steinhardt, R., Monaco, M.L., Huennekens, J., Hickman, A.P.
• Format: Article
• Language: English
• Subjects: Bound–free emission; Excited states; NaK; Transition dipole moment function
• ISSN: 0022-2852; 1096-083X
• DOI: 10.1016/j.jms.2010.11.004

Bound–bound and bound–free spectra are fit to determine a dipole moment function. [Display omitted] ► Bound–free and bound–bound spectra of NaK are fit with a dipole moment function M( R). ► Previously measured and new spectra from high-lying levels are included in the fit. ► The results are consistent with previous work of Burns et al. from this laboratory. ► The fitted M( R), is consistent with recent calculations of Magnier et al. The relative transition dipole moment function M( R) for the 4 3Σ + → a 3Σ + electronic transition in the sodium–potassium molecule (NaK) has been determined by fitting experimental bound–free and bound–bound emission spectra. The fit is performed using a modified version of the BCONT computer program, which was originally developed by Le Roy. Spectra previously measured in this laboratory from low-lying ro-vibrational levels of the 4 3Σ + state and new spectra from high-lying levels are included in the fit. A slight adjustment to the inner, repulsive wall of the 4 3Σ + potential leads to an improved form for that curve. The fitted M( R), when appropriately scaled, agrees very well with recent ab initio calculations of Magnier et al.