Radiative transition probabilities for the main diatomic electronic systems of N₂, N₂ ⁺, NO, O₂, CO, CO⁺, CN, C₂ and H₂ produced in plasma of atmospheric entry

Accurate radiative transition probabilities of diatomic electronic systems are required to calculate the discrete radiation of plasmas. However, most of the published transition probabilities are obtained using older spectroscopic constants and electronic transition moment functions (ETMFs), some of which deviates greatly from experimental data. Fortunately, a lot of new spectroscopic constants that include more anharmonic correction terms than the earlier ones have been published over the past few years. In this work, the Einstein coefficients, Franck–Condon factors and absorption band oscillator strengths are calculated for important diatomic radiative transition processes of N₂-O₂, CO₂-N₂ and H₂ plasmas produced in entering into the atmosphere of Earth, Mars and Jupiter. The most up-to-date spectroscopic constants are selected to reconstruct the potential energy curves by the Rydberg–Klein–Rees (RKR) method. Then the vibrational wave functions are calculated through the resolution of the radial Schrödinger equation for such potential energy curves. These results, together with the latest “ab-initio” ETMFs derived from the literature are used to compute the square of electronic-vibrational transition moments, Einstein coefficients and absorption band oscillator strengths. Moreover, the Franck–Condon factors are determined with the obtained vibrational wave functions. In the supplementary material we present tables of the radiative transition probabilities for 40 band systems of N₂, N₂ ⁺, NO, O₂, CO, CO⁺, CN, C₂ and H₂ molecules. In addition, the calculated radiative lifetimes are systematically validated by available experimental results.