Die Kristallstruktur des wasserfreien Chrom(II)‐chlorides

The crystal structure of anhydrous chromium dichloride (CrCl 2 ) has been determined by the X‐ray powder method. CrCl 2 has an orthorhombic elementary cell with a = 6,624 ± O.006 Å b = 5,974 ± 0,006 Å, c = 3,488 ± 0,004 Å, space group D   2h 12 ‐ Pnnm . The values for the only free parameters x cl and y cl have been refined by a least squares treatment. The structure of CrCl 2 is related to the PdCl 2 structure and, as expected from the crystal field theory, to the structure of CuCl 2 . Each Cr atom is surrounded nearly quadratically by four Cl atoms at a distance of 2,37 5 Å and two Cl atoms at 2,91 Å, completing a deformed octahedron.