The chemistry and physics of group 14 elements such as silicon and germanium have been extensively studied, largely due to their fundamental importance in the development of semiconductor electronics. In addition, crystalline open-framework and nano-porous materials are attracting increasing attention for their potential technological applications. Inorganic open-framework materials comprised of group 14 elements crystallizing in crystal structures known as clathrates are of particular interest. These materials correspond to expanded forms, and in some cases metastable allotropes, of silicon, germanium and tin. The novel crystal structures these materials possess are intimately related to the unique physical properties they exhibit. Just as interesting as the structure and properties group 14 clathrates display is the diverse range of synthetic techniques developed to synthesize and grow single crystals of these materials. This volume will encompass many of these aspects and describe their potential for important technological applications.