GeSb$_{2}$Te$_{4}$ Structure: AB2C4_hR7_166_a_c_2c-002
| Prototype | GeSb$_{2}$Te$_{4}$ |
| AFLOW prototype label | AB2C4_hR7_166_a_c_2c-002 |
| ICSD | 30393 |
| Pearson symbol | hR7 |
| Space group number | 166 |
| Space group symbol | $R\overline{3}m$ |
| AFLOW prototype command |
aflow --proto=AB2C4_hR7_166_a_c_2c-002
--params=$a, \allowbreak c/a, \allowbreak x_{2}, \allowbreak x_{3}, \allowbreak x_{4}$ |
Other compounds with this structure
GeBi$_{2}$Te$_{4}$, PbSb$_{2}$Te$_{4}$, SnSb$_{2}$Te$_{4}$
- This structure is nearly identical to MnBi$_{2}$Te$_{4}$, but the assumed ordering of the tellurium atoms is different in the two cases.
- We use the data from (Agaev, 1966) as reported by (Matsunaga, 2004), however the ICSD entry states that all of the (2c) sites have occupancy Te$_{0.66}$Sb$_{33}$. We follow (Matsunaga, 2004) and label the first (2c) site as Sb with the other two Te, preserving the stiochiometry.
- Hexagonal settings of this structure can be obtained with the option
--hex.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}\\\mathbf{a_{2}}&=&\frac{1}{\sqrt{3}}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}\\\mathbf{a_{3}}&=&- \frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $0$ | = | $0$ | (1a) | Ge I |
| $\mathbf{B_{2}}$ | = | $x_{2} \, \mathbf{a}_{1}+x_{2} \, \mathbf{a}_{2}+x_{2} \, \mathbf{a}_{3}$ | = | $c x_{2} \,\mathbf{\hat{z}}$ | (2c) | Sb I |
| $\mathbf{B_{3}}$ | = | $- x_{2} \, \mathbf{a}_{1}- x_{2} \, \mathbf{a}_{2}- x_{2} \, \mathbf{a}_{3}$ | = | $- c x_{2} \,\mathbf{\hat{z}}$ | (2c) | Sb I |
| $\mathbf{B_{4}}$ | = | $x_{3} \, \mathbf{a}_{1}+x_{3} \, \mathbf{a}_{2}+x_{3} \, \mathbf{a}_{3}$ | = | $c x_{3} \,\mathbf{\hat{z}}$ | (2c) | Te I |
| $\mathbf{B_{5}}$ | = | $- x_{3} \, \mathbf{a}_{1}- x_{3} \, \mathbf{a}_{2}- x_{3} \, \mathbf{a}_{3}$ | = | $- c x_{3} \,\mathbf{\hat{z}}$ | (2c) | Te I |
| $\mathbf{B_{6}}$ | = | $x_{4} \, \mathbf{a}_{1}+x_{4} \, \mathbf{a}_{2}+x_{4} \, \mathbf{a}_{3}$ | = | $c x_{4} \,\mathbf{\hat{z}}$ | (2c) | Te II |
| $\mathbf{B_{7}}$ | = | $- x_{4} \, \mathbf{a}_{1}- x_{4} \, \mathbf{a}_{2}- x_{4} \, \mathbf{a}_{3}$ | = | $- c x_{4} \,\mathbf{\hat{z}}$ | (2c) | Te II |
References
- T. Matsunaga and N. Yamada, Structural investigation of GeSb$_{2}$Te$_{4}$: A high-speed phase-change material, Phys. Rev. B 69, 104111 (2004), doi:10.1103/PhysRevB.69.104111.
- K. A. Agaev and A. G. Talybov, Electron-diffraction analysis of structure of GeSb$_{2}$Te$_{4}$, Sov. Phys. Crystallogr. 11, 400 (1966).
Prototype Generator
aflow --proto=AB2C4_hR7_166_a_c_2c --params=$a,c/a,x_{2},x_{3},x_{4}$