Ab initio the thermodynamic properties and UV spectrum of AlCl+

AlCl+ as a potential interstellar molecule has attracted significant attention, but gaps remain in our understanding of its thermodynamic properties and spectral line intensities. This study employed the icMRCI+Q method to compute potential energy curves for the 13 Lambda-S states of AlCl+. Based on these curves, spectroscopic parameters and vibrational-rotational energy levels were determined. Subsequently, partition functions were calculated over a temperature range from 50 K to 10000 K, and the thermodynamic properties were derived. Using transition dipole moments, the UV spectra for transitions from the ground state (X (2)Sigma(+)) to the third excited state (2(2)Pi) were computed at 298.15 K.