Crystal structures of the compounds R3CuSe6 (R = Gd, Tb and Dy) and TbCu0.34Te2

The crystal structures of the compounds R3CuSe6 (R = Gd, Tb and Dy) (Sm3CuSe6 structure type, space group Pbcm, Pearson symbol oP40) and TbCu0.34Te2 (LaCu0.28Te2 structure type, space group Pbcm, Pearson symbol oP.13.36) were determined by means of X-ray powder diffraction: a = 0.70902(3) nm, b = 0.77850(3) nm, c = 1.68576(7) nm, R-1 = 0.0882 (Gd3CuSe6); a = 0.70630(3) nm, b = 0.77396(3) nm, c = 1.67913(8) nm, R-1 = 0.0806 (Tb3CuSe6); a = 0.70463(4) nm, b = 0.76962(4) nm, c = 1.6680(l) nm, R-1 = 0.0928 (Dy3CuSe6); a 0.75580(3) nm, b = 0.81753(3) nm, c = 0.60828(2) nm, R-1 = 0.0864 (TbCu0.34Te2). (C) 2004 Elsevier B.V. All rights reserved.