Transition probabilities in the A 2Σ+−X 2Πi electronic system of OH

Abstract

A complete set of experimental vibrational band transition probabilities, including recent measurements on $v^{\prime }\text{=2}$ and 3, allows us to calculate an empirical electronic transition moment, $R_e\mathrm{(r),}$ for the ${\mathrm{A\hspace{0.17em}}}^2{\Sigma }^{+}{\mathrm{-X\hspace{0.17em}}}^2{\Pi }_i$ system of OH, over the range of internuclear distance 0.70–1.70 Å. A comparison with an ab initio moment confirms that theoretical shape and validates its quantitative results, as the calculated $R_e\mathrm{(r)}$ is within experimental uncertainty of the present result. The experimentally derived $R_e\mathrm{(r)}$ is used along with Rydberg–Klein–Rees (RKR) wave functions to calculate transition probabilities for a wide range of vibrational and rotational levels. The study is extended to the isotope OD.