2019MNRAS.487.3427D

Time-independent close-coupling quantum scattering calculations are employed to compute hyperfine-resolved rate coefficients for (de-)excitation of SH⁺ in collisions with para- and ortho-H₂. These calculations utilized a potential energy surface for the interaction of SH⁺(X³Σ^–) with H₂ recently computed by the explicitly correlated RCCSD(T)-F12a coupled-cluster method. Rate coefficients for temperatures ranging from 10 to 500 K were calculated for all transitions among the first 37 hyperfine energy levels of SH⁺, with rotational angular momenta n <= 6, in collisions with para- and ortho-H₂. As a first application of these data, the rate coefficients were employed in simple radiative transfer calculations to simulate the excitation of SH⁺ in typical molecular clouds.