Thermal propertiesThermal properties D 3000Preparation, Structure and Thermal Properties of CuGa 5 Se 8 . -Crystals of the title compound are prepared by the horizontal Bridgman method from the elements. As revealed by powder XRD, the samples are single-phased and exhibit a chalcopyrite-related structure. The thermal expansion behavior of the compound is the same as for CuGa 3 Se 5 and CuIn 3 Se 5 and shows relatively small expansivity along the c-axis and a large one in the perpendicular direction at any temperature between 90 and 650 K. The X-ray Debye temperature of the title compound obtained from the analysis of the temperature dependence of Bragg reflections intensity is in moderate agreement with that evaluated from the melting point. -(ORLOVA*, N. S.; BODNAR, I. V.; KUSHNER, T. L.; Cryst.