Global modelling of the observed line positions: Dunham coefficients for the ground state of ¹⁶OH molecule

Abstract

A global treatment of the available experimental data on infrared and microwave transitions of 33 vibration-rotation bands for the ground state and the data on the electronic system B²Σ⁺-X²Π of ¹⁶OH molecule was carried out. In this analysis, a global model with vibrational dependences of the parameters of the effective Hamiltonian for the diatomic molecule in the ²Π electronic state was used. As a result of the fit, a set of the ‘Dunham-type’ coefficients was obtained. They reproduce the experimental dataset of the rovibrational and pure rotational transitions as well as the data on the electronic system B²Σ⁺ - X²Π, within estimated experimental uncertainties. The determined ‘Dunham-type’ coefficients were compared with those known previously.

GRAPHICAL ABSTRACT

KEYWORDS:

• Hydroxyl radical
• observed transition frequencies
• ‘Dunham-type’ coefficients
• molecular parameters

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Ministry of Science and Higher Education of the Russian Federation (V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Sciences).