Combined X-ray and neutron diffraction study of K2[Pt(CN)4]X 0.3.3H2O with X = Br, Cl(KCP) between 31 K and room temperature

The results of six crystal structure refinements of K2[Pt(CN)4]X0. 3. 3H20 with X = Br, C1 (KCP) from X-ray and neutron diffraction measurements between 31 K and room temperature are presented and compared. Particular subjects of the discussion are the parameters of the [Pt(CN) 4] groups, the distribution of the water molecules, and the temperature dependence of the temperature factors. The Pt-Pt distances deviate from each other by less than 0.007 A. The [Pt(CN) 4] groups are not planar. X-ray data show a correlation between the z parameters of the K atoms and (CN) groups. Zero-point vibrations and the magnitude of the positional disorder of the various atoms are derived from their temperature factors at different temperatures.