6533b82cfe1ef96bd128f713

RESEARCH PRODUCT

Aluminum-lithium clusters: First-principles simulation of geometries and electronic properties

subject

description

The geometries and electronic properties of small lithium-rich ${\mathrm{Al}}_{N}{\mathrm{Li}}_{5N}$ $(N=1--6,10)$ clusters are studied using first-principles simulations. Aluminum ions form a compact inner core configuration in the clusters that changes into a chainlike skeleton embedded in a lithium surrounding as the cluster size increases. This behavior restricts $s\ensuremath{-}p$ hybridization effects and causes separate s and p bands in the electronic energy spectrum. A significant charge transfer from Li ions and nearby Al ions strengthens ionic Al-Li bonds, while Al-Al bonds gain a more covalent nature. The evolution of some bulk properties of $B2$ and $B32$ phases of AlLi alloys is studied by constructing 59- and 145-atom ${\mathrm{Al}}_{N}{\mathrm{Li}}_{M}$ $(N\ensuremath{\approx}M)$ clusters based on a truncated rhombic dodecahedron. Tetrahedrally coordinated covalent Al-Al bonds of $B32$ clusters affect the electronic properties and hardness.