Multiply charged metal cluster anions

Formation and stability patterns of silver dianionic and gold trianionic cl usters are investigated with Penning-trap experiments and a shell-correctio n method including shape deformations. The theoretical predictions pertaini ng to the appearance sizes and electronic shell effects are in remarkable a greement with the experiments. Decay of the multiply anionic clusters occur s predominantly by electron tunneling through a Coulomb barrier rather than via fission, leading to appearance sizes unrelated to those of multiply ca tionic clusters.