Sr$_{2}$NiWO$_{6}$ Structure: AB6C2D_tI20_87_a_eh_d_b-001
| Prototype | NiO$_{6}$Sr$_{2}$W |
| AFLOW prototype label | AB6C2D_tI20_87_a_eh_d_b-001 |
| ICSD | 91791 |
| Pearson symbol | tI20 |
| Space group number | 87 |
| Space group symbol | $I4/m$ |
| AFLOW prototype command |
aflow --proto=AB6C2D_tI20_87_a_eh_d_b-001
--params=$a, \allowbreak c/a, \allowbreak z_{4}, \allowbreak x_{5}, \allowbreak y_{5}$ |
Other compounds with this structure
Sr$_{2}$MgWO$_{6}$
- This double perovskite crystal is the ground state structure of Sr$_{2}$NiWO$_{6}$. Above 300°C it transforms into the cubic perovskite $E2_{1}$ structure.
- (Iwanga, 2000) places the strontium atoms on the (4c) Wyckoff position, but gives the coordinates for the (4d) site. The interatomic distances they give with this structure are consistent with the (4d) site.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&- \frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{2}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{3}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}- \frac{1}{2}c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $0$ | = | $0$ | (2a) | Ni I |
| $\mathbf{B_{2}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}$ | = | $\frac{1}{2}c \,\mathbf{\hat{z}}$ | (2b) | W I |
| $\mathbf{B_{3}}$ | = | $\frac{3}{4} \, \mathbf{a}_{1}+\frac{1}{4} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{4}c \,\mathbf{\hat{z}}$ | (4d) | Sr I |
| $\mathbf{B_{4}}$ | = | $\frac{1}{4} \, \mathbf{a}_{1}+\frac{3}{4} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{4}c \,\mathbf{\hat{z}}$ | (4d) | Sr I |
| $\mathbf{B_{5}}$ | = | $z_{4} \, \mathbf{a}_{1}+z_{4} \, \mathbf{a}_{2}$ | = | $c z_{4} \,\mathbf{\hat{z}}$ | (4e) | O I |
| $\mathbf{B_{6}}$ | = | $- z_{4} \, \mathbf{a}_{1}- z_{4} \, \mathbf{a}_{2}$ | = | $- c z_{4} \,\mathbf{\hat{z}}$ | (4e) | O I |
| $\mathbf{B_{7}}$ | = | $y_{5} \, \mathbf{a}_{1}+x_{5} \, \mathbf{a}_{2}+\left(x_{5} + y_{5}\right) \, \mathbf{a}_{3}$ | = | $a x_{5} \,\mathbf{\hat{x}}+a y_{5} \,\mathbf{\hat{y}}$ | (8h) | O II |
| $\mathbf{B_{8}}$ | = | $- y_{5} \, \mathbf{a}_{1}- x_{5} \, \mathbf{a}_{2}- \left(x_{5} + y_{5}\right) \, \mathbf{a}_{3}$ | = | $- a x_{5} \,\mathbf{\hat{x}}- a y_{5} \,\mathbf{\hat{y}}$ | (8h) | O II |
| $\mathbf{B_{9}}$ | = | $x_{5} \, \mathbf{a}_{1}- y_{5} \, \mathbf{a}_{2}+\left(x_{5} - y_{5}\right) \, \mathbf{a}_{3}$ | = | $- a y_{5} \,\mathbf{\hat{x}}+a x_{5} \,\mathbf{\hat{y}}$ | (8h) | O II |
| $\mathbf{B_{10}}$ | = | $- x_{5} \, \mathbf{a}_{1}+y_{5} \, \mathbf{a}_{2}- \left(x_{5} - y_{5}\right) \, \mathbf{a}_{3}$ | = | $a y_{5} \,\mathbf{\hat{x}}- a x_{5} \,\mathbf{\hat{y}}$ | (8h) | O II |
References
- D. Iwanaga, Y. Inaguma, and M. Itoh, Structure and Magnetic Properties of Sr$_{2}$NiAO$_{6}$ (A = W, Te), Mater. Res. Bull. 35, 449–457 (2000), doi:10.1016/S0025-5408(00)00222-1.
Prototype Generator
aflow --proto=AB6C2D_tI20_87_a_eh_d_b --params=$a,c/a,z_{4},x_{5},y_{5}$