Configuration Interaction of Electronic Structure and Spectroscopy of AlH and Its Cation^*

We carry out a detailed study of the low-lying states of AlH and AlH⁺, using a multireference configuration interaction method. Based on the computed potential energy curves, the spectroscopic constants of bound Λ–S states are fitted; these agree with the results for the measurements. The values of the permanent dipole moment of the Λ–S states are calculated, and the charge transfer mechanism is discussed. Based on the calculated transition dipole moments and vibrational levels, the radiative lifetimes of bound states are determined. Finally, tunneling lifetimes, and ν′ = 0–2 vibrational levels of 4² Σ ⁺ and 3² Π states with a potential barrier are investigated. (paper)