In recent years there have been a revival of interest§in discovering and understanding the physical§properties of novel thermoelectric (TE) materials§with high figure of merit. These materials are§primarily narrow band gap semiconductors. In this§book, electronic structure calculations were carried§out for several narrow band gap chalcogenide TE§materials in order to understand their electronic and§transport properties governing their TE§characteristics. These calculations were performed§within DFT whereas the transport calculations were§carried out using Boltzmann transport...