Chapter 1. Chevrel-Phases: Genesis and Developments.- Chapter 2. Octahedral chalcogenide rhenium clusters: From solids to isolated cluster complexes.- Chapter 3.Exploring the Breadth of Terminal Ligands Coordinated in [Mo6X8]4+ and [Re6Q8]2+ Based Cluster Complexes.- Chapter 4. Rhenium Hexanuclear clusters: Bonding, spectroscopy and Applications of Molecular Chevrel Phases.- Chapter 5.- Thermoelectric Properties of Ternary and Quaternary Mo6 and Mo9 Cluster Selenides.- Chapter 6. Inorganic Niobium and Tantalum Octahedral Cluster Halide Compounds with Three-dimensional Frameworks: A Review on their Crystallographic and Electronic Structures.