Structural and electronic properties of aluminum-based binary clusters - art. no. 155409

We investigate the low-energy geometries and the electronic structure of se veral aluminum based clusters, viz. Al4X4, (X=Li, Na, K, Be, Mg, B, and Si) by first principle Born-Oppenheimer molecular dynamics within the framewor k of density-functional theory. We present a systematic analysis of the bon ding properties and discuss the validity of spherical jellium model. We fin d that the structure of eigenstates for clusters with metallic elements con form to the spherical jellium model. The 20 valence electron systems Al4Be4 and Al4Mg4 exhibit a large highest-occupied-lowest-unoccupied (HOMO-LUMO) gap due to shell closing effect. In clusters containing alkali-metal atom, Al-4 behaves as a superatom that is ionically bonded to them. The Al-Al bon d in both Al4Si4 and Al4B4 clusters is found to be covalent.