Density-functional theory study of Aln and Aln−1Mg (n = 2–17) clusters

The equilibrium geometries, relative stabilities, both vertical and adiabatic of ionization potentials and electron affinities as well electronic properties of Aln and Aln−1Mg (n = 2–17) clusters have been systematically investigated by using B3LYP/6-311G(d). In general, the ground state structures of Aln−1Mg clusters have similar geometries as the host Aln clusters, except for Al4Mg. Starting from n = 7, the Mg atom prefers to stay away from the center of Aln clusters and locate on the site of the corresponding Aln clusters surface. The dissociation energy of the Aln−1Mg clusters dissociate into Aln−1 clusters with one Mg atom are lower than those dissociate into Aln−2Mg clusters with one Al atom, which suggests that the Aln−1Mg clusters are likely to break into Aln−1 clusters with one Mg atom. The results of AEA and VEA, AIP and VIP and second-order difference energy indicate that the Aln−1Mg (n = 3, 5, 7, 9, 11, 13, 15, and 17) clusters are more stable than others, which reveals that the chemical activity of Aln−1Mg clusters are diminished. The electronic structure has been discussed and the results of natural charge population analysis shows that there is a charge transfer from 3s states of Mg atom to 3p states of Al atoms resulting in the strong s-p hybridization.