RENNER-TELLER ROVIBRONIC SPECTRUM OF THE HCS RADICAL AND THE ROVIBRATIONAL SPECTRUM OF HCS

Using highly correlated electronic wavefunctions, the three-dimensional potential energy, electric dipole and electronic transition moment functions have been calculated for the first two electronic states of the HCS radical. Both states form a Renner-Teller pair, the lower has a bent equilibrium structure, the upper is linear. The results of the electronic structure calculations have been used in solutions of the nuclear motion problem. The standard perturbation theory results for the rovibrational levels will be compared with the variational rovibrational and rovibronic Renner-Teller results. In the calculation of the radiative transition probabilities between the rovibronic states contributions from the electric dipole moment functions of both electronic states as well as the electronic transition moment function have been considered. The rovibronic spectrum of the hitherto unkown HCS radical will be predicted. For the HCS-ion the rovibrational terms and radiative transition probabilities will be predicted. In these calculations the rotational-vibrational coupling has been fully accounted for.