SmSI Structure: ABC_hR6_166_c_c_c
| Prototype | : | SmSI |
| AFLOW prototype label | : | ABC_hR6_166_c_c_c |
| Strukturbericht designation | : | None |
| Pearson symbol | : | hR6 |
| Space group number | : | 166 |
| Space group symbol | : | $R\bar{3}m$ |
| AFLOW prototype command | : | aflow --proto=ABC_hR6_166_c_c_c [--hex] --params=$a,c/a,x_{1},x_{2},x_{3}$ |
Other compounds with this structure
- β–CeSI, PrSI, NdSI, and the superconducting alkali metal intercalcates β–MNX (M = Zr, Hf; X = Cl, Br, I).
- Although this has the same crystallographic structure as the C12 structure, the layering is substantially different.
Rhombohedral primitive vectors:
\[
\begin{array}{ccc}
\mathbf{a}_1 & = & ~ \frac12 \, a \, \mathbf{\hat{x}} - \frac{1}{2\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13 \, c \, \mathbf{\hat{z}} \\
\mathbf{a}_2 & = & \frac{1}{\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13 \, c \, \mathbf{\hat{z}} \\
\mathbf{a}_3 & = & - \frac12 \, a \, \mathbf{\hat{x}} - \frac{1}{2\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13 \, c \, \mathbf{\hat{z}} \\
\end{array}
\]
Basis vectors:
\[ \begin{array}{ccccccc} & & \mbox{Lattice Coordinates} & & \mbox{Cartesian Coordinates} &\mbox{Wyckoff Position} & \mbox{Atom Type} \\ \mathbf{B}_{1} & = & x_{1} \, \mathbf{a}_{1} + x_{1} \, \mathbf{a}_{2} + x_{1} \, \mathbf{a}_{3} & = & x_{1}c \, \mathbf{\hat{z}} & \left(2c\right) & \mbox{I} \\ \mathbf{B}_{2} & = & -x_{1} \, \mathbf{a}_{1}-x_{1} \, \mathbf{a}_{2}-x_{1} \, \mathbf{a}_{3} & = & -x_{1}c \, \mathbf{\hat{z}} & \left(2c\right) & \mbox{I} \\ \mathbf{B}_{3} & = & x_{2} \, \mathbf{a}_{1} + x_{2} \, \mathbf{a}_{2} + x_{2} \, \mathbf{a}_{3} & = & x_{2}c \, \mathbf{\hat{z}} & \left(2c\right) & \mbox{S} \\ \mathbf{B}_{4} & = & -x_{2} \, \mathbf{a}_{1}-x_{2} \, \mathbf{a}_{2}-x_{2} \, \mathbf{a}_{3} & = & -x_{2}c \, \mathbf{\hat{z}} & \left(2c\right) & \mbox{S} \\ \mathbf{B}_{5} & = & x_{3} \, \mathbf{a}_{1} + x_{3} \, \mathbf{a}_{2} + x_{3} \, \mathbf{a}_{3} & = & x_{3}c \, \mathbf{\hat{z}} & \left(2c\right) & \mbox{Sm} \\ \mathbf{B}_{6} & = & -x_{3} \, \mathbf{a}_{1}-x_{3} \, \mathbf{a}_{2}-x_{3} \, \mathbf{a}_{3} & = & -x_{3}c \, \mathbf{\hat{z}} & \left(2c\right) & \mbox{Sm} \\ \end{array} \]References
- H. P. Beck and C. Strobel, Zur Hochdruckpolymorphie der Seltenerdsulfidiodide LnSI, Z. Anorg. Allg. Chem. 535, 229–239 (1986), doi:10.1002/zaac.19865350427.
Found in
- A. M. Fogg, J. S. O. Evens, and D. {O'Hare}, Crystal structure of β–MNX (M = Zr, Hf; X = Cl, Br), Chem. Comm. 0, 2269–2270 (1998), doi:10.1039/A806415F.