SmSI Structure: ABC_hR6_166_c_c_c

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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.

Geometry files


Prototype Generator

aflow --proto=ABC_hR6_166_c_c_c --params=

Species:

Running:

Output: