Metal clusters are on the brink between molecules and nanoparticles in size. With molecular, nano-scale, metallic as well as non-metallic aspects, metal clusters are a growing, interdisciplinary field with numerous potential applications in chemistry, catalysis, materials and nanotechnology. This third volume in the series of hot topics from inorganic chemistry covers all recent developments in the field of metal clusters, with some 20 contributions providing an in-depth view. The result is a unique perspective, illustrating all facets of this interdisciplinary area: Inter-electron Repulsion and Irregularities in the Chemistry of Transition Series Stereochemical Activity of Lone Pairs in Heavier Main Group Element Compounds How Close to Close Packing? Forty-Five Years of Praseodymium Diiodide Centered Zirconium Clusters Titanium Niobium Oxychlorides Trinuclear Molybdenum and Tungsten Cluster Chalcogenides Current State of (B,C,N)-Compounds of Calcium and Lanthanum Ternary Phases of Lithium with Main-Group and Late-Transition Metals Polar Intermetallics and Zintl Phases along the Zintl Border Rare Earth Zintl Phases Structure-Property Relationships in Intermetallics Ternary and Quaternary Niobium Arsenide Zintl Phases The Building Block Approach to Understanding Main-Group-Metal Complex Structures Cation-Deficient Quaternary Thiospinels A New Class of Hybrid Materials via Salt Inclusion Synthesis Layered Perrhenate and Vanadate Hybrid Solids Hydrogen Bonding in Metal Halides Syntheses and Catalytic Properties of Titanium Nitride Nanoparticles Solventless Thermolysis New Potential Scintillation Materials in Borophosphate Systems. With its didactical emphasis, this volume addresses a wide readership, such that both students and specialists will profit from the expert contributions.