Crystal structure data and refinement results for \mathrm{Sr}_{2} \mathrm{MWO}_{6}(\mathrm{M}=\mathrm{Ni}, \mathrm{Zn}, \mathrm{Co}, \mathrm{Cu}). The atomic positions were refined in the space group I 4 / m. (The five atoms in the asymmetric unit occupy the following sites: W 2a ( 0,0,0); Ni, Zn, Co or Cu 2b ( 0,0,1 / 2); Sr 4c ( 0,1 / 2,1 / 4); O1 8h (x, y, 0) and O2 4e (0,0, z).)
| \mathrm{Sr}_{2} \mathrm{NiWO}_{6} | \mathrm{Sr}_{2} \mathrm{ZnWO}_{6}^{\mathrm{a}} | \mathrm{Sr}_{2} \mathrm{CoWO}_{6} | \mathrm{Sr}_{2} \mathrm{CuWO}_{6} | |
|---|---|---|---|---|
| a (Å) | 5.5608(1) | 5.5973(2) | 5.5820(1) | 5.4291(1) |
| c (Å) | 7.9191(1) | 7.9889(3) | 7.9774(1) | 8.4154(1) |
| O1 (x) | 0.209(2) | 0.202(2) | 0.201(1) | 0.202(1) |
| O1 (y) | 0.280(2) | 0.292(2) | 0.274(1) | 0.298(1) |
| O2 (z) | 0.244(1) | 0.241(2) | 0.238(1) | 0.224(1) |
| R_{\mathrm{p}}(\%) | 8.58 | 9.72 | 11.8 | 15.3 |
| R_{\mathrm{wp}} (%) | 10.2 | 12.1 | 16.3 | 15.9 |
| R_{\text {exp }} (%) | 4.96 | 5.37 | 7.63 | 8.57 |
| \chi^{2} | 4.23 | 5.08 | 4.26 | 3.45 |