Cluster chemistry is one of the latest topic in Inorganic Chemistry. In chemistry, a cluster compound is considered as a compound with a triangular or larger closed polyhedron of metal atoms. Clusters exist in various stoichiometries and nuclearities. For example, carbon and boron atoms form fullerene and borane clusters. Transition metals and main group elements form robust clusters. cluster was the term introduced by F.A. Cotton to refer to compounds containing metal–metal bonds.clusters include: Atomic clusters , Molecular clusters, Transition metal carbonyl clusters, Transition metal halide clusters, Boron hydrides, Fe-S clusters in biology, Zintl clusters, Metalloid clusters, Catalysis by metal carbonyl clusters.