Fine-structure transitions of Si, S, N⁺ and O²⁺ induced by collisions with atomic hydrogen

Atomic and ionic fine-structure emission lines are widely observed in astronomy. For the spectra to be useful diagnostics of astrophysical environments collisional excitation and relaxation rate coefficients describing interactions with ambient particles are needed. Here we consider the case of collisions with atomic hydrogen. Based on accurate SiH, SH, NH⁺ and OH²⁺ molecular potentials, we will report calculations of fine-structure excitation and relaxation cross sections and rate coefficients in collisions of Si, S, N⁺ and O²⁺ with H utilizing a fully-quantum close-coupling method. Applications of the resulting data and extensions of the methodology to other colliding systems will be discussed.