Clustering behaviour in M8K6 bimetallic clusters (M=Li, Na, K, Rb, Cs, Mg and Al):: A density based molecular dynamic study

Clustering behaviour of the constituent alkali metals, in bimetallic clusters has been investigated for M8K6 clusters (M=Li, K, Rb, Cs Mg and Al) using a recently developed orbital free molecular dynamics method. For Li8K6 and Na8K6 the lithium or sodium atoms form a distorted inner cube whose six faces are capped by K atoms. In contrast, for Rb8K6, and Cs8K6, the K atoms form an inner octahedron whose faces are capped by Rb or Cs atoms. The homoatomic K-14 and Al-14 clusters form in icosahedral configuration with one of its face being capped by the fourteenth atom. For Mg8K6 and Al8K6 Clusters. the Mg or Al atoms form a distorted cubic inner core of the cluster. From these results, it is inferred that for such bimetallic clusters the element with smaller atomic radius, higher electronegativity. and larger number of valence electrons, forms the core of the cluster.