GROUND-STATE GEOMETRIES AND ENERGETICS OF AL(N)LI (N=1,13) CLUSTERS USING AB-INITIO DENSITY-BASED MOLECULAR-DYNAMICS

Based on orbital-free ab initio molecular dynamics calculations, the g eometries and energetics of lithium-doped aluminium clusters (AlnLi, n = 1, 13) have been investigated. It is seen that, a single impurity o f Li affects the geometries of small (n < 6) clusters, and this effect is less pronounced for larger clusters. The results suggest extra sta bility for the Al3Li, Al6Li and A(13)Li clusters, which are in contras t with our earlier results on LinAl. The results indicate that the Li atom segregates to the surface of the aluminium cluster and prefers to form a tetrahedron, wherever possible, with one of the triangular fac es of Al atoms. In particular, for Al13Li, the Al-13 core takes the mo st symmetric icosahedral form with the Li atom occupying the outer 'ho llow-site'.