Quintet electronic states of N2.

We use large scale ab initio calculations to investigate the valence and valence-Rydberg quintet states of N(2), their transition moments and their spin-orbit couplings to the close lying triplet electronic states. In addition to the A' (5)Sigma(g)(+) and the C" (5)Pi(ui) states already known, we identify two weakly bound states (2 (5)Sigma(g)(+) and 2 (5)Pi(u)) at approximately 95,300 and 106,200 cm(-1) above N(2)(X (1)Sigma(g)(+), v=0). The other quintets are viewed to be repulsive in nature. Our potentials and couplings are used later to derive a set of accurate spectroscopic data for these quintets, their spin-orbit constants, and to elucidate the quintet-triplet dynamics and the role of these newly identified quintets for the production of cold atomic nitrogen.

Spectroscopy, metastability, and single and double ionization of AlCl.

Large calculations are done to investigate the valence and inner-valence electronic states of aluminum monochloride and its cationic species AlCl+ and AlCl2+, allowing their definite assignment. This concerns particularly the computations of the potential-energy curves of the electronic states of these species and their spin-orbit couplings and transition moments. An accurate set of spectroscopic constants for these species is also deduced. For the neutral molecule, our calculations show that the lifetimes of the AlCl A1pi v' > or = 10 levels are reduced to the 0.1-0.01 ps time scale because of spin-orbit induced predissociation processes and by tunneling through the potential barrier of the A state. Our potential curves for the ground state of AlCl and those of the cationic and dicationic species are also used for predicting the single and double ionization spectrum of AlCl. For both the cation and the dication, long-lived rovibrational levels are predicted.