Ab initio calculations on the ground and excited electronic states of AsI molecule including spin-orbit coupling

Abstract Eleven Λ-S states and five Ω states of AsI molecule are calculated at the method of multireference configuration interaction plus Davidson correction (MRCI + Q), and the equilibrium bond length (Re), electron transition energy (Te), harmonic vibrational frequency (ωe), non-harmonic vibrational frequency (ωeΧe) and rotational constant (Be) of these states are fitted. The permanent dipole moments of eleven Λ-S states are also calculated in this paper. On account of the accurate potential energy curves and the transition dipole moment, the Franck-Condon factors and radiative lifetime of the b 1 Σ 0 + +  ↔  X 3 Σ 0 + - transition for AsI molecule are calculated. Although it has highly diagonalized Franck-Condon factors, its radiative lifetime is only ms level. The feasibility of laser cooling of AsI molecules is analyzed by comparing it with the monohalide of Group-IIIA.