Ro-vibrational excitation of SiS by He

Modelling of the astrophysical spectra requires accurate radiative and collisional rates for species of astrophysical interest. The present paper focuses on the calculation of ro-vibrational excitation rate coefficients of SiS by He, useful for studies of high-temperature interstellar . A new accurate three-dimensional potential energy surface for the SiS-He system, which explicitly takes into account the r-dependence of the SiS vibration, was determined from ab initio calculations. The dynamic calculations were performed using the vibrational close-coupling rotational infinite order sudden (VCC-IOS) method. Cross sections among the first 100 rotational levels of v = 0-4 are calculated for total energies up to 12 000 cm(-1). Rate coefficients between the ro-vibrational levels are calculated for temperatures from 300 K to 1500 K.