Theoretical study of the electronic states of AlB

Abstract

The singlet, triplet, and quintet states of AlB below about 30 000 cm−1 are studied theoretically to facilitate spectroscopic investigations and for comparison with analogous calculations on the Al2 and B2 molecules. The ground state of AlB is X 3Σ− with a dissociation energy of 1.96±0.06 eV. The A 3Π state is computed to lie only 610 cm−1 above the ground state. Since transitions from the (2)3Σ− state to both the X 3Σ− and A 3Π states are predicted to be relatively strong, these transitions in the region of 17 000–18 000 cm−1 should be an excellent means of characterizing AlB and of determining the X−A separation. The adiabatic ionization potential to form the X 2Σ+ ground state of AlB+ is estimated to be 7.05 eV. Overall the spectroscopy of AlB is much more similar to Al2 than B2.