GeTe Structure: AB_hR2_160_a_a-002
- This is a distortion of the rock salt ($B1$) structure, and GeTe undergoes a phase transition to the rock salt structure above 300°C. When $\alpha = 60° (c/a = \sqrt{6})$ and $z_{2}-z_{1} = 1/2$ this becomes the rock salt structure.
- Space group $R3m$ #160 does not specify the origin of the $z$-axis. Here we arbitrarily set $z_{1} = 0$.
- 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 | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $x_{1} \, \mathbf{a}_{1}+x_{1} \, \mathbf{a}_{2}+x_{1} \, \mathbf{a}_{3}$ | = | $c x_{1} \,\mathbf{\hat{z}}$ | (1a) | Ge I |
| $\mathbf{B_{2}}$ | = | $x_{2} \, \mathbf{a}_{1}+x_{2} \, \mathbf{a}_{2}+x_{2} \, \mathbf{a}_{3}$ | = | $c x_{2} \,\mathbf{\hat{z}}$ | (1a) | Te I |
References
- T. Nonaka, G. Ohbayashi, Y. Toriumi, Y. Mori, and H. Hashimoto, Crystal structure of GeTe and Ge$_{2}$Sb$_{2}$Te$_{5}$ meta-stable phase, Thin Solid Films 370, 258–261 (2000), doi:10.1016/S0040-6090(99)01090-1.
First cited in
- H. Eckert, S. Divilov, M. J. Mehl, D. Hicks, A. C. Zettel, M. Esters, X. Campilongo, and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 4, Comp. Mat. Sci. 240, 112988 (2024). (doi=10.1016/j.commatsci.2021.110450)
Geometry files
Prototype Generator
aflow --proto=AB_hR2_160_a_a --params=$a,c/a,x_{1},x_{2}$