Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: A2B8C11_tI84_139_h_deim_eh2n-001

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Sc$_{11}$Al$_{2}$Ge$_{8}$ Structure: A2B8C11_tI84_139_h_deim_eh2n-001

Picture of Structure; Click for Big Picture
Prototype Al$_{2}$Ge$_{8}$Sc$_{11}$
AFLOW prototype label A2B8C11_tI84_139_h_deim_eh2n-001
ICSD 184236
CCDC 1693480
Pearson symbol tI84
Space group number 139
Space group symbol $I4/mmm$
AFLOW prototype command aflow --proto=A2B8C11_tI84_139_h_deim_eh2n-001
--params=$a, \allowbreak c/a, \allowbreak z_{2}, \allowbreak z_{3}, \allowbreak x_{4}, \allowbreak x_{5}, \allowbreak x_{6}, \allowbreak x_{7}, \allowbreak z_{7}, \allowbreak y_{8}, \allowbreak z_{8}, \allowbreak y_{9}, \allowbreak z_{9}$

Other compounds with this structure

Er$_{11}$Al$_{2}$Ge$_{8}$,  Gd$_{11}$In$_{2}$Ge$_{8}$,  Yb$_{11}$Sn$_{2}$Bi$_{8}$


  • This is a tenary form of Ho$_{11}$Ge$_{10}$. The ICSD lists all these compounds using the Ho$_{11}$Ge$_{10}$ prototype. We arbitrarily chose Sc$_{11}$Al$_{2}$Ge$_{8}$ as the prototype.
  • Tb$_{11}$Si$_{4}$In$_{6}$ is a second ternary form of Ho$_{11}$Ge$_{10}$.
  • The AFLOW standard labeling algorithm shifts the origin by (0.5 a, 0.5 b, 0), moving the Ge III atom from the published (8j) Wyckoff position to (8i).

\[ \begin{array}{ccc} \mathbf{a_{1}}&=&- \frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{2}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{3}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}- \frac{1}{2}c \,\mathbf{\hat{z}} \end{array}\]

Basis vectors

Lattice coordinates Cartesian coordinates Wyckoff position Atom type
$\mathbf{B_{1}}$ = $\frac{3}{4} \, \mathbf{a}_{1}+\frac{1}{4} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{4}c \,\mathbf{\hat{z}}$ (4d) Ge I
$\mathbf{B_{2}}$ = $\frac{1}{4} \, \mathbf{a}_{1}+\frac{3}{4} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{4}c \,\mathbf{\hat{z}}$ (4d) Ge I
$\mathbf{B_{3}}$ = $z_{2} \, \mathbf{a}_{1}+z_{2} \, \mathbf{a}_{2}$ = $c z_{2} \,\mathbf{\hat{z}}$ (4e) Ge II
$\mathbf{B_{4}}$ = $- z_{2} \, \mathbf{a}_{1}- z_{2} \, \mathbf{a}_{2}$ = $- c z_{2} \,\mathbf{\hat{z}}$ (4e) Ge II
$\mathbf{B_{5}}$ = $z_{3} \, \mathbf{a}_{1}+z_{3} \, \mathbf{a}_{2}$ = $c z_{3} \,\mathbf{\hat{z}}$ (4e) Sc I
$\mathbf{B_{6}}$ = $- z_{3} \, \mathbf{a}_{1}- z_{3} \, \mathbf{a}_{2}$ = $- c z_{3} \,\mathbf{\hat{z}}$ (4e) Sc I
$\mathbf{B_{7}}$ = $x_{4} \, \mathbf{a}_{1}+x_{4} \, \mathbf{a}_{2}+2 x_{4} \, \mathbf{a}_{3}$ = $a x_{4} \,\mathbf{\hat{x}}+a x_{4} \,\mathbf{\hat{y}}$ (8h) Al I
$\mathbf{B_{8}}$ = $- x_{4} \, \mathbf{a}_{1}- x_{4} \, \mathbf{a}_{2}- 2 x_{4} \, \mathbf{a}_{3}$ = $- a x_{4} \,\mathbf{\hat{x}}- a x_{4} \,\mathbf{\hat{y}}$ (8h) Al I
$\mathbf{B_{9}}$ = $x_{4} \, \mathbf{a}_{1}- x_{4} \, \mathbf{a}_{2}$ = $- a x_{4} \,\mathbf{\hat{x}}+a x_{4} \,\mathbf{\hat{y}}$ (8h) Al I
$\mathbf{B_{10}}$ = $- x_{4} \, \mathbf{a}_{1}+x_{4} \, \mathbf{a}_{2}$ = $a x_{4} \,\mathbf{\hat{x}}- a x_{4} \,\mathbf{\hat{y}}$ (8h) Al I
$\mathbf{B_{11}}$ = $x_{5} \, \mathbf{a}_{1}+x_{5} \, \mathbf{a}_{2}+2 x_{5} \, \mathbf{a}_{3}$ = $a x_{5} \,\mathbf{\hat{x}}+a x_{5} \,\mathbf{\hat{y}}$ (8h) Sc II
$\mathbf{B_{12}}$ = $- x_{5} \, \mathbf{a}_{1}- x_{5} \, \mathbf{a}_{2}- 2 x_{5} \, \mathbf{a}_{3}$ = $- a x_{5} \,\mathbf{\hat{x}}- a x_{5} \,\mathbf{\hat{y}}$ (8h) Sc II
$\mathbf{B_{13}}$ = $x_{5} \, \mathbf{a}_{1}- x_{5} \, \mathbf{a}_{2}$ = $- a x_{5} \,\mathbf{\hat{x}}+a x_{5} \,\mathbf{\hat{y}}$ (8h) Sc II
$\mathbf{B_{14}}$ = $- x_{5} \, \mathbf{a}_{1}+x_{5} \, \mathbf{a}_{2}$ = $a x_{5} \,\mathbf{\hat{x}}- a x_{5} \,\mathbf{\hat{y}}$ (8h) Sc II
$\mathbf{B_{15}}$ = $x_{6} \, \mathbf{a}_{2}+x_{6} \, \mathbf{a}_{3}$ = $a x_{6} \,\mathbf{\hat{x}}$ (8i) Ge III
$\mathbf{B_{16}}$ = $- x_{6} \, \mathbf{a}_{2}- x_{6} \, \mathbf{a}_{3}$ = $- a x_{6} \,\mathbf{\hat{x}}$ (8i) Ge III
$\mathbf{B_{17}}$ = $x_{6} \, \mathbf{a}_{1}+x_{6} \, \mathbf{a}_{3}$ = $a x_{6} \,\mathbf{\hat{y}}$ (8i) Ge III
$\mathbf{B_{18}}$ = $- x_{6} \, \mathbf{a}_{1}- x_{6} \, \mathbf{a}_{3}$ = $- a x_{6} \,\mathbf{\hat{y}}$ (8i) Ge III
$\mathbf{B_{19}}$ = $\left(x_{7} + z_{7}\right) \, \mathbf{a}_{1}+\left(x_{7} + z_{7}\right) \, \mathbf{a}_{2}+2 x_{7} \, \mathbf{a}_{3}$ = $a x_{7} \,\mathbf{\hat{x}}+a x_{7} \,\mathbf{\hat{y}}+c z_{7} \,\mathbf{\hat{z}}$ (16m) Ge IV
$\mathbf{B_{20}}$ = $- \left(x_{7} - z_{7}\right) \, \mathbf{a}_{1}- \left(x_{7} - z_{7}\right) \, \mathbf{a}_{2}- 2 x_{7} \, \mathbf{a}_{3}$ = $- a x_{7} \,\mathbf{\hat{x}}- a x_{7} \,\mathbf{\hat{y}}+c z_{7} \,\mathbf{\hat{z}}$ (16m) Ge IV
$\mathbf{B_{21}}$ = $\left(x_{7} + z_{7}\right) \, \mathbf{a}_{1}- \left(x_{7} - z_{7}\right) \, \mathbf{a}_{2}$ = $- a x_{7} \,\mathbf{\hat{x}}+a x_{7} \,\mathbf{\hat{y}}+c z_{7} \,\mathbf{\hat{z}}$ (16m) Ge IV
$\mathbf{B_{22}}$ = $- \left(x_{7} - z_{7}\right) \, \mathbf{a}_{1}+\left(x_{7} + z_{7}\right) \, \mathbf{a}_{2}$ = $a x_{7} \,\mathbf{\hat{x}}- a x_{7} \,\mathbf{\hat{y}}+c z_{7} \,\mathbf{\hat{z}}$ (16m) Ge IV
$\mathbf{B_{23}}$ = $\left(x_{7} - z_{7}\right) \, \mathbf{a}_{1}- \left(x_{7} + z_{7}\right) \, \mathbf{a}_{2}$ = $- a x_{7} \,\mathbf{\hat{x}}+a x_{7} \,\mathbf{\hat{y}}- c z_{7} \,\mathbf{\hat{z}}$ (16m) Ge IV
$\mathbf{B_{24}}$ = $- \left(x_{7} + z_{7}\right) \, \mathbf{a}_{1}+\left(x_{7} - z_{7}\right) \, \mathbf{a}_{2}$ = $a x_{7} \,\mathbf{\hat{x}}- a x_{7} \,\mathbf{\hat{y}}- c z_{7} \,\mathbf{\hat{z}}$ (16m) Ge IV
$\mathbf{B_{25}}$ = $\left(x_{7} - z_{7}\right) \, \mathbf{a}_{1}+\left(x_{7} - z_{7}\right) \, \mathbf{a}_{2}+2 x_{7} \, \mathbf{a}_{3}$ = $a x_{7} \,\mathbf{\hat{x}}+a x_{7} \,\mathbf{\hat{y}}- c z_{7} \,\mathbf{\hat{z}}$ (16m) Ge IV
$\mathbf{B_{26}}$ = $- \left(x_{7} + z_{7}\right) \, \mathbf{a}_{1}- \left(x_{7} + z_{7}\right) \, \mathbf{a}_{2}- 2 x_{7} \, \mathbf{a}_{3}$ = $- a x_{7} \,\mathbf{\hat{x}}- a x_{7} \,\mathbf{\hat{y}}- c z_{7} \,\mathbf{\hat{z}}$ (16m) Ge IV
$\mathbf{B_{27}}$ = $\left(y_{8} + z_{8}\right) \, \mathbf{a}_{1}+z_{8} \, \mathbf{a}_{2}+y_{8} \, \mathbf{a}_{3}$ = $a y_{8} \,\mathbf{\hat{y}}+c z_{8} \,\mathbf{\hat{z}}$ (16n) Sc III
$\mathbf{B_{28}}$ = $- \left(y_{8} - z_{8}\right) \, \mathbf{a}_{1}+z_{8} \, \mathbf{a}_{2}- y_{8} \, \mathbf{a}_{3}$ = $- a y_{8} \,\mathbf{\hat{y}}+c z_{8} \,\mathbf{\hat{z}}$ (16n) Sc III
$\mathbf{B_{29}}$ = $z_{8} \, \mathbf{a}_{1}- \left(y_{8} - z_{8}\right) \, \mathbf{a}_{2}- y_{8} \, \mathbf{a}_{3}$ = $- a y_{8} \,\mathbf{\hat{x}}+c z_{8} \,\mathbf{\hat{z}}$ (16n) Sc III
$\mathbf{B_{30}}$ = $z_{8} \, \mathbf{a}_{1}+\left(y_{8} + z_{8}\right) \, \mathbf{a}_{2}+y_{8} \, \mathbf{a}_{3}$ = $a y_{8} \,\mathbf{\hat{x}}+c z_{8} \,\mathbf{\hat{z}}$ (16n) Sc III
$\mathbf{B_{31}}$ = $\left(y_{8} - z_{8}\right) \, \mathbf{a}_{1}- z_{8} \, \mathbf{a}_{2}+y_{8} \, \mathbf{a}_{3}$ = $a y_{8} \,\mathbf{\hat{y}}- c z_{8} \,\mathbf{\hat{z}}$ (16n) Sc III
$\mathbf{B_{32}}$ = $- \left(y_{8} + z_{8}\right) \, \mathbf{a}_{1}- z_{8} \, \mathbf{a}_{2}- y_{8} \, \mathbf{a}_{3}$ = $- a y_{8} \,\mathbf{\hat{y}}- c z_{8} \,\mathbf{\hat{z}}$ (16n) Sc III
$\mathbf{B_{33}}$ = $- z_{8} \, \mathbf{a}_{1}+\left(y_{8} - z_{8}\right) \, \mathbf{a}_{2}+y_{8} \, \mathbf{a}_{3}$ = $a y_{8} \,\mathbf{\hat{x}}- c z_{8} \,\mathbf{\hat{z}}$ (16n) Sc III
$\mathbf{B_{34}}$ = $- z_{8} \, \mathbf{a}_{1}- \left(y_{8} + z_{8}\right) \, \mathbf{a}_{2}- y_{8} \, \mathbf{a}_{3}$ = $- a y_{8} \,\mathbf{\hat{x}}- c z_{8} \,\mathbf{\hat{z}}$ (16n) Sc III
$\mathbf{B_{35}}$ = $\left(y_{9} + z_{9}\right) \, \mathbf{a}_{1}+z_{9} \, \mathbf{a}_{2}+y_{9} \, \mathbf{a}_{3}$ = $a y_{9} \,\mathbf{\hat{y}}+c z_{9} \,\mathbf{\hat{z}}$ (16n) Sc IV
$\mathbf{B_{36}}$ = $- \left(y_{9} - z_{9}\right) \, \mathbf{a}_{1}+z_{9} \, \mathbf{a}_{2}- y_{9} \, \mathbf{a}_{3}$ = $- a y_{9} \,\mathbf{\hat{y}}+c z_{9} \,\mathbf{\hat{z}}$ (16n) Sc IV
$\mathbf{B_{37}}$ = $z_{9} \, \mathbf{a}_{1}- \left(y_{9} - z_{9}\right) \, \mathbf{a}_{2}- y_{9} \, \mathbf{a}_{3}$ = $- a y_{9} \,\mathbf{\hat{x}}+c z_{9} \,\mathbf{\hat{z}}$ (16n) Sc IV
$\mathbf{B_{38}}$ = $z_{9} \, \mathbf{a}_{1}+\left(y_{9} + z_{9}\right) \, \mathbf{a}_{2}+y_{9} \, \mathbf{a}_{3}$ = $a y_{9} \,\mathbf{\hat{x}}+c z_{9} \,\mathbf{\hat{z}}$ (16n) Sc IV
$\mathbf{B_{39}}$ = $\left(y_{9} - z_{9}\right) \, \mathbf{a}_{1}- z_{9} \, \mathbf{a}_{2}+y_{9} \, \mathbf{a}_{3}$ = $a y_{9} \,\mathbf{\hat{y}}- c z_{9} \,\mathbf{\hat{z}}$ (16n) Sc IV
$\mathbf{B_{40}}$ = $- \left(y_{9} + z_{9}\right) \, \mathbf{a}_{1}- z_{9} \, \mathbf{a}_{2}- y_{9} \, \mathbf{a}_{3}$ = $- a y_{9} \,\mathbf{\hat{y}}- c z_{9} \,\mathbf{\hat{z}}$ (16n) Sc IV
$\mathbf{B_{41}}$ = $- z_{9} \, \mathbf{a}_{1}+\left(y_{9} - z_{9}\right) \, \mathbf{a}_{2}+y_{9} \, \mathbf{a}_{3}$ = $a y_{9} \,\mathbf{\hat{x}}- c z_{9} \,\mathbf{\hat{z}}$ (16n) Sc IV
$\mathbf{B_{42}}$ = $- z_{9} \, \mathbf{a}_{1}- \left(y_{9} + z_{9}\right) \, \mathbf{a}_{2}- y_{9} \, \mathbf{a}_{3}$ = $- a y_{9} \,\mathbf{\hat{x}}- c z_{9} \,\mathbf{\hat{z}}$ (16n) Sc IV

References

  • J. T. Zhao and E. Parthé, Sc$_{11}$Al$_{2}$Ge$_{8}$, a ternary substitution variant of the tetragonal Ho$_{11}$Ge$_{10}$ type, Acta Crystallogr. Sect. C 47, 4–6 (1991), doi:10.1107/S0108270190007314.

First cited in

  • N. Anderson, M. J. Mehl, H. Eckert, S. Divilov, X. Campilongo, S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 5. Submitted to Computational Materials Science (2026).

Geometry files


Prototype Generator

aflow --proto=A2B8C11_tI84_139_h_deim_eh2n --params=$a,c/a,z_{2},z_{3},x_{4},x_{5},x_{6},x_{7},z_{7},y_{8},z_{8},y_{9},z_{9}$

Species:

Running:

Output: