An unstable anion stabilized in a molecular trap

The possibility of stabilizing an electronically metastable anion in a mole cular trap is studied using ab initio electronic structure methods. The (2) Pi(g) N-2(-) d-wave shape resonance state is used as a prototype for the me tastable anion solute. and a pair of inwardly oriented LiCN molecules (NCLi ... LiCN) is used as a prototypical trap. It is found that for the (NCLi . .. LiCN) trap at its local minimum geometry, the (2)Pi(g), state becomes el ectronically stable and is the ground state of the system. It is also found that, in this model trap, two other (excited) anionic states are bound ((2 )Sigma(g) and (2)Pi(u)) one of which is a trap-bound state and the second o f which is another stabilized resonance state. Moreover, calculations perfo rmed on traps of varying strength (which we alter by varying the trap size) show that the number of bound anionic states strongly depends on the trap' s strength. Detailed numerical results are presented for the (NCLi ... N=N ... LiCN)(-) trap plus solute anion whose vertical electron detachment ener gy is 3.250 eV, but the results obtained are suggestive of a wide variety o f such trap-stabilized anion systems.