Multireference calculations on low-lying states and X³Π_u-³Π_g absorption spectra of indium dimer

Multireference configuration interaction calculations are carried out on eleven Λ-S low-lying electronic states of indium dimer. The Ω states are investigated with spin-orbit pseudopotentials via state-interacting method, and characterized with fitted spectroscopic constants based on computed potential energy curves. The vibrational structures of double-potential well 0_g⁺(I) (³Σ _g^-) state are analyzed. The experimentally observed absorption spectrum centred at ～ 13000 cm^-1 is simulated and assigned to X³Π_u (v' =0)-³Π _g transition according to the present ab initio calculations on transition energies and dipole moments functions.