A NEW INVESTIGATION OF RUBIDIUM CADMIUM TRICHLORIDE

The structure of RbCdCl3 has been determined from X-ray diffraction of the MoK alpha line (lambda = 0.7107 Angstrom) for a single crystal gr own at room temperature from aqueous solution. After refinement throug h blocked least-squares methods, the reliability factor R in the final cycle was 3.31%, using 1955 observed reflections with I greater than or equal to 2 sigma(I). The following results have been obtained, in g ood agreement with previous powder measurements:orthorhombic system, s pace group Pnma (D-2h), a = 8.962 Angstrom, b = 4.034 Angstrom, c = 14 .980 Angstrom; D-m = 3.732 g/cm(3), D-x = 3.736 g/cm(3), F(000) = 543. 90; Z = 4. Double columns of edge-sharing CdCl6 octahedra (Cd-Cl = 2.6 47 Angstrom) extending along b are linked by nine coordinated Rb ions (Rb-Cl = 3.366 Angstrom) into a compact structure. (C) 1996 Academic P ress, Inc.