STRUCTURE REFINEMENT OF CuInSe₂ BY CCD CAMERA. K. Suda,* H. Kitahara,* N. Ishizawa* and Y. Noda,** Research Laboratory of Engineering Materials, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-Ku, Yokohama 226, Japan,* Department of Materials Science, Faculty of Engineering, Tohoku University, Aramaki, Aoba-ku, Sendai 980-77, Japan

Three-circle diffractometer equipped with a charge-coupled device (CCD) camera has been used for collecting three-dimensional diffraction data of CuInSe₂ inorganic crystal and the results were compared with those obtained by the conventional four-circle diffractometer. Crystals were grown by the traveling heater method using pure In as the solvent. The distance between the crystal and the phosphor plate was fixed at about 30 mm. Since the peaks have sharp profiles compared to the organic ones, the [[omega]] scan width of a frame was taken to be 0.15deg.. The crystal of CuInSe₂ is tetragonal with the space group I42d. Cell dimensions of a=5.7852(1) Å and c=11.6254(4) Å were determined from 1961 reflections. In all, 2542 frames were taken to cover a hemisphere of the reciprocal space in the range (sin[[theta]])/[[lambda]][[second]]0.81 Å^-1. Integrated intensities of 2334 reflections were retrieved from the frame data. It took about 12 hours to finish all measurement. The same crystal as used for the CCD experiment was mounted on a Ag rotating-anode four-circle diffractometer. The integrated intensities of 1024 reflections within a quadrant of reciprocal space in the range (sin[[theta]])/[[lambda]][[second]]0.81 Å^-1 were measured using 2[[theta]]-[[omega]] scan technique with AgK[[alpha]] radiation monochromated by graphite (004). It took about 4 days to finish all of the measurement. Structural parameters obtained after the least-squares refinement generally agreed well within errors. Final R values were 0.0319 for 340 independent reflections obtained by the CCD diffractometer and 0.0171 for 402 independent reflections obtained by the four-circle diffractometer in the same range. Although the R factor of the CCD data set was slightly worse due to the relatively large disagreement between the observed and calculated structure factors of weak reflections, the CCD camera system was proved to be a useful equipment for the structural study of inorganic compounds as well as for organic and macromolecule compounds.