2020MNRAS.494.5239D

Accurate estimates of the abundance of H₂S, and inferences about the unmeasured H₂ density, require accurate knowledge of radiative and collisional rate coefficients. Time-independent close-coupling quantum scattering calculations have been employed to compute rate coefficients for (de-)excitation of para- and ortho-H₂S in collisions with para- and ortho-H₂. These calculations utilized a potential energy surface for the interaction of H₂S with H₂ recently computed by the explicitly correlated CCSD(T)-F12a coupled-cluster method. Rate coefficients for temperatures ranging from 5 to 500 K were calculated for all transitions among the first 19 rotational levels of H₂S, whose energies are less than or equal to 405 K. These rate coefficients are compared with previous estimates of these quantities.