Radiative Lifetime Calculations of Selected Ro-vibrational Levels of Excited NaK 1(B)¹Π and Li₂ 4¹Σ_g⁺ Dimers

We report on the status of radiative lifetime calculations of excited states of two different dimers. Selected ro-vibrational levels of the NaK 1(B)¹Π and Li₂ 4¹Σ_g⁺ states have been studied to determine Einstein coefficients corresponding to transitions to lower energy states.  We use the programs created by R. J. Le Roy, specifically LEVEL and a modified version of BCONT. For more information or to download Le Roys programs, see https://uwaterloo.ca/atmospheric-chemistry-experiment/leroy-programs. LEVEL is used to calculate Einstein coefficients for bound-bound transitions and BCONT is used to compute the equivalent coefficients for bound-free transitions. The calculated Einstein coefficients are used to determine the radiative lifetime using this expression: τ_i^-1=∑_α' ( ∑_fA_if + ∫₀^E(α')Γ_if^α'dE), where the α' term represents the final electronic state in the transition. In this lifetime equation, the A_if term is the bound-bound Einstein coefficient and the Γ_if^α' term is the photon emission rate for bound-free transitions. Results of these calculated radiative lifetimes are compared to experimentally determined, collision-free lifetimes measured by the Burcin Bayram group at Miami University in Oxford, Ohio.