Spectrochim Acta A Mol Biomol Spectrosc 2019 Jul 8;218:184-190. Epub 2019 Apr 8.
College of Physics and Material Science, Henan Normal University, Xinxiang 453007, China. Electronic address:
The potential energy curves are calculated for the aΠ, bΣ, cΣ, dΠ, and eΣ states of the AlO cation using the valence internally contracted multireference configuration interaction approach. The transition dipole moments are computed between these states. To improve the reliability and accuracy of the potential energy curves, several corrections are included, namely, Davidson correction, core-valence correlation and scalar relativistic corrections, as well as extrapolation of the potential energies to the complete basis set limit. The rotationless radiative lifetimes of all vibrational levels are of the orders of 10 to 10 s for the bΣ state, which are so long that the transitions generating from the bΣ state are almost impossible to occur. Those are several ten to several hundred ns for the eΣ state, and several μs for the cΣ and dΠ states, which indicate that the transitions originating from the eΣ, cΣ, and dΠ states occur easily. The largest Einstein coefficient of the transitions from the bΣ-aΠ system is approximately 10, suggesting that these transitions are too weak to be recorded through spectroscopy. The Einstein coefficients of many transitions from the cΣ-aΠ, dΠ-aΠ, dΠ-cΣ, and eΣ-aΠ systems are large, indicating that these transitions are able to be measured via spectroscopy. The transition properties reported in this study can be employed to detect the spectroscopy from the AlO cation both in outer space and in experiment.