Behavior of magnesium clusters under electron attachment and detachment

Electronic-structure studies on neutral, anionic, and singly and doubly charged cationic ${\mathrm{Mg}}_{\mathrm{n}}$ clusters (n≤6) have been carried out within the local spin-density functional formalism. We present results on their equilibrium geometries and discuss their stability. We find the geometry of anionic clusters to have the same symmetry as corresponding neutral clusters. The stability of anionic clusters comes from the filling of a bonding orbital formed mainly of atomic p orbitals invariant under the symmetry group of the cluster. The calculated electron affinities are in excellent agreement with recent experimental values.