2019MNRAS.485.2791F

A detailed line list of spectroscopic transitions between the triplet states of the ZrS molecule at high temperature is presented. Transitions were calculated between the rotational and vibrational energy levels of the five triplet states (1)³Δ, (1)³Π, (2)³Π, (1)³Φ, and (1)³Σ⁺. The potential energy curves were calculated by using the method of Multireference Configuration Interaction (MRSDCI). In the calculations we used the augmented basis set aug-cc-pVQZ-PP with relativistic effective core potentials (ECPs). Spin-orbit calculations were then included by using a spin-orbit pseudo-potential (ECP) for zirconium and the Breit-Pauli operator for sulfur. The obtained ab initio potential energy curves were corrected by fitting to experimental results. Permanent and transition dipole moments were further computed in MRSDCI+Q calculations. These calculations were then used to obtain an accurate absorption line list of hot ZrS up to a temperature of 4000 K. The calculated spectroscopic line list is formed from over 7.5 million transitions between almost 22 619 rovibrational energy levels. The calculated line lists have a frequency range between 0 and 20 000 cm^–1 formed by including all transitions within the lowest five triplet states. To investigate the effect of temperature on the spectrum we calculated the partition function within the temperature range 10 to 4000 K. The presented line list is the most complete list available for the triplet states of ZrS at high temperature. The present work should help to identify the spectrum of gaseous ZrS in cool stars and exoplanetary atmospheres.