Relativistic calculations on the transition electric dipole moments and radiative lifetimes of the spin-forbidden transitions in the antimony hydride molecule

Calculations on the spectroscopic constants and transition properties of the first three states (a 1 Δ, b 1 Σ + , and X 3 Σ − ) of the SbH molecule were performed under the relativistic framework using the exact two-component Hamiltonian (X2C). The potential energy curves in the Franck–Condon region were computed and compared with the previous values. Furthermore, the transition dipole moments for the weak spin-forbidden transitions (b0 + –X 1 0 + , b0 + –X 2 1, X 1 0 + –X 2 1, and X 2 1–a2) were reported. The spontaneous radiative lifetime of the b 1 Σ + ( υ ′ = 0) state was calculated as 163.5±7.5 μ s, which is in reasonable agreement with the latest experimental value of 173±3 μ s. The spontaneous radiative lifetimes of the X 2 1 ( υ ′ = 0) state and the a2 ( υ ′ = 0) state were calculated to be 48.6 s and ∼ 8 ms, respectively. Our study is expected to be a benchmark transition property computation for comparison with other theoretical and experimental results. The datasets presented in this paper, including the transition dipole moments, are openly available at https://dx.doi.org/10.11922/sciencedb.j00113.00018 .