Crystal structure data and refinement results for \mathrm{Na}_{0.5} \mathrm{K}_{0.5} \mathrm{NbO}_{3} determined using neutron diffraction data at 10 K using the R 3 c space group. Cell parameters: a=5.6188(6) \AA, c=13.7873(4) \AA, V= 376.96(1) \AA^{3}.
| Atom | Site | x | y | z | \left.B_{\text {iso }}{ }^{2}\right) |
|---|---|---|---|---|---|
| \mathrm{Na} / \mathrm{K} | 6 a | 0 | 0 | 0.2656(3) | 0.94(5) |
| Nb | 6 a | 0 | 0 | 0.0086(2) | 0.55(1) |
| O 1 | 18 b | 0.6630(4) | 0.8178(4) | 0.0752(1) | 0.22(1) |