Conclusions
The structures, relative stability, and electronic properties of the lowest-energy AlBen (n = 1–12) clusters were systematically studied by high-level ab initio and density functional theories. The geometry transformation from planar to steroescopic occurs at AlBe3 in this series. The impurity Al atom prefers to reside ouside the host Ben cluster until n = 12 and only slightly affects the configuration of the latter. NBO analysis reveals that 0.167~2.403|e| charge flows from the host Ben to the Al atom, which might be due to the larger electronegativity of Al than Be. The evolutions ofEb , Δ2E , ΔE ,E ad, and HOMO-LUMO gap with cluster size show special stability of AlBe3 and AlBe8among the AlBen clusters. Moreover, a comparison has been made between AlBen and pure beryllium clusters, and it is found that substituting an Al atom for a Be atom in Ben +1 results in enhanced binding energy and polarizability but decreased chemical hardness of the system.