Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: AB9C2_oC96_65_acg_ghoq3r_2g2h-001

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BaIr$_{2}$Ge$_{7}$ Structure: AB9C2_oC96_65_acg_ghoq3r_2g2h-001

Picture of Structure; Click for Big Picture
Prototype BaGe$_{7}$Ir$_{2}$
AFLOW prototype label AB9C2_oC96_65_acg_ghoq3r_2g2h-001
ICSD 194234
CCDC 1702930
Pearson symbol oC96
Space group number 65
Space group symbol $Cmmm$
AFLOW prototype command aflow --proto=AB9C2_oC96_65_acg_ghoq3r_2g2h-001
--params=$a, \allowbreak b/a, \allowbreak c/a, \allowbreak x_{3}, \allowbreak x_{4}, \allowbreak x_{5}, \allowbreak x_{6}, \allowbreak x_{7}, \allowbreak x_{8}, \allowbreak x_{9}, \allowbreak x_{10}, \allowbreak z_{10}, \allowbreak x_{11}, \allowbreak y_{11}, \allowbreak x_{12}, \allowbreak y_{12}, \allowbreak z_{12}, \allowbreak x_{13}, \allowbreak y_{13}, \allowbreak z_{13}, \allowbreak x_{14}, \allowbreak y_{14}, \allowbreak z_{14}$

  • BaIr$_{2}$Ge$_{7}$ and Ba$_{3}$Ir$_{4}$Ge$_{16}$ are structures with the barium atoms surrounded by germanium rings and germanium-iridium cages. They are superconducting at 2.5 and 5.2K, respectively.
  • (Ishida, 2014), wishing to present the structure with the long axis in the $\hat{z}$ direction, give the structural data for BaIr$_{2}$Ge$_{7}$ in the $Ammm$ setting of space group #65. We used AFLOW to transform this to the standard $Cmmm$ setting. This rotates the lattice 90$^\circ$ about the y-axis. In addition the origin was translated by 1/2\,b\,$\hat{y}$, moving the first barium atom from the (2b) site to the origin at the (2a) site.
  • The Ge VI and Ge VII (16r) sites are only half-occupied, leading to the observed stoichiometry.

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

Basis vectors

Lattice coordinates Cartesian coordinates Wyckoff position Atom type
$\mathbf{B_{1}}$ = $0$ = $0$ (2a) Ba I
$\mathbf{B_{2}}$ = $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (2c) Ba II
$\mathbf{B_{3}}$ = $x_{3} \, \mathbf{a}_{1}+x_{3} \, \mathbf{a}_{2}$ = $a x_{3} \,\mathbf{\hat{x}}$ (4g) Ba III
$\mathbf{B_{4}}$ = $- x_{3} \, \mathbf{a}_{1}- x_{3} \, \mathbf{a}_{2}$ = $- a x_{3} \,\mathbf{\hat{x}}$ (4g) Ba III
$\mathbf{B_{5}}$ = $x_{4} \, \mathbf{a}_{1}+x_{4} \, \mathbf{a}_{2}$ = $a x_{4} \,\mathbf{\hat{x}}$ (4g) Ge I
$\mathbf{B_{6}}$ = $- x_{4} \, \mathbf{a}_{1}- x_{4} \, \mathbf{a}_{2}$ = $- a x_{4} \,\mathbf{\hat{x}}$ (4g) Ge I
$\mathbf{B_{7}}$ = $x_{5} \, \mathbf{a}_{1}+x_{5} \, \mathbf{a}_{2}$ = $a x_{5} \,\mathbf{\hat{x}}$ (4g) Ir I
$\mathbf{B_{8}}$ = $- x_{5} \, \mathbf{a}_{1}- x_{5} \, \mathbf{a}_{2}$ = $- a x_{5} \,\mathbf{\hat{x}}$ (4g) Ir I
$\mathbf{B_{9}}$ = $x_{6} \, \mathbf{a}_{1}+x_{6} \, \mathbf{a}_{2}$ = $a x_{6} \,\mathbf{\hat{x}}$ (4g) Ir II
$\mathbf{B_{10}}$ = $- x_{6} \, \mathbf{a}_{1}- x_{6} \, \mathbf{a}_{2}$ = $- a x_{6} \,\mathbf{\hat{x}}$ (4g) Ir II
$\mathbf{B_{11}}$ = $x_{7} \, \mathbf{a}_{1}+x_{7} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $a x_{7} \,\mathbf{\hat{x}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (4h) Ge II
$\mathbf{B_{12}}$ = $- x_{7} \, \mathbf{a}_{1}- x_{7} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $- a x_{7} \,\mathbf{\hat{x}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (4h) Ge II
$\mathbf{B_{13}}$ = $x_{8} \, \mathbf{a}_{1}+x_{8} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $a x_{8} \,\mathbf{\hat{x}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (4h) Ir III
$\mathbf{B_{14}}$ = $- x_{8} \, \mathbf{a}_{1}- x_{8} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $- a x_{8} \,\mathbf{\hat{x}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (4h) Ir III
$\mathbf{B_{15}}$ = $x_{9} \, \mathbf{a}_{1}+x_{9} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $a x_{9} \,\mathbf{\hat{x}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (4h) Ir IV
$\mathbf{B_{16}}$ = $- x_{9} \, \mathbf{a}_{1}- x_{9} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $- a x_{9} \,\mathbf{\hat{x}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (4h) Ir IV
$\mathbf{B_{17}}$ = $x_{10} \, \mathbf{a}_{1}+x_{10} \, \mathbf{a}_{2}+z_{10} \, \mathbf{a}_{3}$ = $a x_{10} \,\mathbf{\hat{x}}+c z_{10} \,\mathbf{\hat{z}}$ (8o) Ge III
$\mathbf{B_{18}}$ = $- x_{10} \, \mathbf{a}_{1}- x_{10} \, \mathbf{a}_{2}+z_{10} \, \mathbf{a}_{3}$ = $- a x_{10} \,\mathbf{\hat{x}}+c z_{10} \,\mathbf{\hat{z}}$ (8o) Ge III
$\mathbf{B_{19}}$ = $- x_{10} \, \mathbf{a}_{1}- x_{10} \, \mathbf{a}_{2}- z_{10} \, \mathbf{a}_{3}$ = $- a x_{10} \,\mathbf{\hat{x}}- c z_{10} \,\mathbf{\hat{z}}$ (8o) Ge III
$\mathbf{B_{20}}$ = $x_{10} \, \mathbf{a}_{1}+x_{10} \, \mathbf{a}_{2}- z_{10} \, \mathbf{a}_{3}$ = $a x_{10} \,\mathbf{\hat{x}}- c z_{10} \,\mathbf{\hat{z}}$ (8o) Ge III
$\mathbf{B_{21}}$ = $\left(x_{11} - y_{11}\right) \, \mathbf{a}_{1}+\left(x_{11} + y_{11}\right) \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $a x_{11} \,\mathbf{\hat{x}}+b y_{11} \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (8q) Ge IV
$\mathbf{B_{22}}$ = $- \left(x_{11} - y_{11}\right) \, \mathbf{a}_{1}- \left(x_{11} + y_{11}\right) \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $- a x_{11} \,\mathbf{\hat{x}}- b y_{11} \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (8q) Ge IV
$\mathbf{B_{23}}$ = $- \left(x_{11} + y_{11}\right) \, \mathbf{a}_{1}- \left(x_{11} - y_{11}\right) \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $- a x_{11} \,\mathbf{\hat{x}}+b y_{11} \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (8q) Ge IV
$\mathbf{B_{24}}$ = $\left(x_{11} + y_{11}\right) \, \mathbf{a}_{1}+\left(x_{11} - y_{11}\right) \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $a x_{11} \,\mathbf{\hat{x}}- b y_{11} \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (8q) Ge IV
$\mathbf{B_{25}}$ = $\left(x_{12} - y_{12}\right) \, \mathbf{a}_{1}+\left(x_{12} + y_{12}\right) \, \mathbf{a}_{2}+z_{12} \, \mathbf{a}_{3}$ = $a x_{12} \,\mathbf{\hat{x}}+b y_{12} \,\mathbf{\hat{y}}+c z_{12} \,\mathbf{\hat{z}}$ (16r) Ge V
$\mathbf{B_{26}}$ = $- \left(x_{12} - y_{12}\right) \, \mathbf{a}_{1}- \left(x_{12} + y_{12}\right) \, \mathbf{a}_{2}+z_{12} \, \mathbf{a}_{3}$ = $- a x_{12} \,\mathbf{\hat{x}}- b y_{12} \,\mathbf{\hat{y}}+c z_{12} \,\mathbf{\hat{z}}$ (16r) Ge V
$\mathbf{B_{27}}$ = $- \left(x_{12} + y_{12}\right) \, \mathbf{a}_{1}- \left(x_{12} - y_{12}\right) \, \mathbf{a}_{2}- z_{12} \, \mathbf{a}_{3}$ = $- a x_{12} \,\mathbf{\hat{x}}+b y_{12} \,\mathbf{\hat{y}}- c z_{12} \,\mathbf{\hat{z}}$ (16r) Ge V
$\mathbf{B_{28}}$ = $\left(x_{12} + y_{12}\right) \, \mathbf{a}_{1}+\left(x_{12} - y_{12}\right) \, \mathbf{a}_{2}- z_{12} \, \mathbf{a}_{3}$ = $a x_{12} \,\mathbf{\hat{x}}- b y_{12} \,\mathbf{\hat{y}}- c z_{12} \,\mathbf{\hat{z}}$ (16r) Ge V
$\mathbf{B_{29}}$ = $- \left(x_{12} - y_{12}\right) \, \mathbf{a}_{1}- \left(x_{12} + y_{12}\right) \, \mathbf{a}_{2}- z_{12} \, \mathbf{a}_{3}$ = $- a x_{12} \,\mathbf{\hat{x}}- b y_{12} \,\mathbf{\hat{y}}- c z_{12} \,\mathbf{\hat{z}}$ (16r) Ge V
$\mathbf{B_{30}}$ = $\left(x_{12} - y_{12}\right) \, \mathbf{a}_{1}+\left(x_{12} + y_{12}\right) \, \mathbf{a}_{2}- z_{12} \, \mathbf{a}_{3}$ = $a x_{12} \,\mathbf{\hat{x}}+b y_{12} \,\mathbf{\hat{y}}- c z_{12} \,\mathbf{\hat{z}}$ (16r) Ge V
$\mathbf{B_{31}}$ = $\left(x_{12} + y_{12}\right) \, \mathbf{a}_{1}+\left(x_{12} - y_{12}\right) \, \mathbf{a}_{2}+z_{12} \, \mathbf{a}_{3}$ = $a x_{12} \,\mathbf{\hat{x}}- b y_{12} \,\mathbf{\hat{y}}+c z_{12} \,\mathbf{\hat{z}}$ (16r) Ge V
$\mathbf{B_{32}}$ = $- \left(x_{12} + y_{12}\right) \, \mathbf{a}_{1}- \left(x_{12} - y_{12}\right) \, \mathbf{a}_{2}+z_{12} \, \mathbf{a}_{3}$ = $- a x_{12} \,\mathbf{\hat{x}}+b y_{12} \,\mathbf{\hat{y}}+c z_{12} \,\mathbf{\hat{z}}$ (16r) Ge V
$\mathbf{B_{33}}$ = $\left(x_{13} - y_{13}\right) \, \mathbf{a}_{1}+\left(x_{13} + y_{13}\right) \, \mathbf{a}_{2}+z_{13} \, \mathbf{a}_{3}$ = $a x_{13} \,\mathbf{\hat{x}}+b y_{13} \,\mathbf{\hat{y}}+c z_{13} \,\mathbf{\hat{z}}$ (16r) Ge VI
$\mathbf{B_{34}}$ = $- \left(x_{13} - y_{13}\right) \, \mathbf{a}_{1}- \left(x_{13} + y_{13}\right) \, \mathbf{a}_{2}+z_{13} \, \mathbf{a}_{3}$ = $- a x_{13} \,\mathbf{\hat{x}}- b y_{13} \,\mathbf{\hat{y}}+c z_{13} \,\mathbf{\hat{z}}$ (16r) Ge VI
$\mathbf{B_{35}}$ = $- \left(x_{13} + y_{13}\right) \, \mathbf{a}_{1}- \left(x_{13} - y_{13}\right) \, \mathbf{a}_{2}- z_{13} \, \mathbf{a}_{3}$ = $- a x_{13} \,\mathbf{\hat{x}}+b y_{13} \,\mathbf{\hat{y}}- c z_{13} \,\mathbf{\hat{z}}$ (16r) Ge VI
$\mathbf{B_{36}}$ = $\left(x_{13} + y_{13}\right) \, \mathbf{a}_{1}+\left(x_{13} - y_{13}\right) \, \mathbf{a}_{2}- z_{13} \, \mathbf{a}_{3}$ = $a x_{13} \,\mathbf{\hat{x}}- b y_{13} \,\mathbf{\hat{y}}- c z_{13} \,\mathbf{\hat{z}}$ (16r) Ge VI
$\mathbf{B_{37}}$ = $- \left(x_{13} - y_{13}\right) \, \mathbf{a}_{1}- \left(x_{13} + y_{13}\right) \, \mathbf{a}_{2}- z_{13} \, \mathbf{a}_{3}$ = $- a x_{13} \,\mathbf{\hat{x}}- b y_{13} \,\mathbf{\hat{y}}- c z_{13} \,\mathbf{\hat{z}}$ (16r) Ge VI
$\mathbf{B_{38}}$ = $\left(x_{13} - y_{13}\right) \, \mathbf{a}_{1}+\left(x_{13} + y_{13}\right) \, \mathbf{a}_{2}- z_{13} \, \mathbf{a}_{3}$ = $a x_{13} \,\mathbf{\hat{x}}+b y_{13} \,\mathbf{\hat{y}}- c z_{13} \,\mathbf{\hat{z}}$ (16r) Ge VI
$\mathbf{B_{39}}$ = $\left(x_{13} + y_{13}\right) \, \mathbf{a}_{1}+\left(x_{13} - y_{13}\right) \, \mathbf{a}_{2}+z_{13} \, \mathbf{a}_{3}$ = $a x_{13} \,\mathbf{\hat{x}}- b y_{13} \,\mathbf{\hat{y}}+c z_{13} \,\mathbf{\hat{z}}$ (16r) Ge VI
$\mathbf{B_{40}}$ = $- \left(x_{13} + y_{13}\right) \, \mathbf{a}_{1}- \left(x_{13} - y_{13}\right) \, \mathbf{a}_{2}+z_{13} \, \mathbf{a}_{3}$ = $- a x_{13} \,\mathbf{\hat{x}}+b y_{13} \,\mathbf{\hat{y}}+c z_{13} \,\mathbf{\hat{z}}$ (16r) Ge VI
$\mathbf{B_{41}}$ = $\left(x_{14} - y_{14}\right) \, \mathbf{a}_{1}+\left(x_{14} + y_{14}\right) \, \mathbf{a}_{2}+z_{14} \, \mathbf{a}_{3}$ = $a x_{14} \,\mathbf{\hat{x}}+b y_{14} \,\mathbf{\hat{y}}+c z_{14} \,\mathbf{\hat{z}}$ (16r) Ge VII
$\mathbf{B_{42}}$ = $- \left(x_{14} - y_{14}\right) \, \mathbf{a}_{1}- \left(x_{14} + y_{14}\right) \, \mathbf{a}_{2}+z_{14} \, \mathbf{a}_{3}$ = $- a x_{14} \,\mathbf{\hat{x}}- b y_{14} \,\mathbf{\hat{y}}+c z_{14} \,\mathbf{\hat{z}}$ (16r) Ge VII
$\mathbf{B_{43}}$ = $- \left(x_{14} + y_{14}\right) \, \mathbf{a}_{1}- \left(x_{14} - y_{14}\right) \, \mathbf{a}_{2}- z_{14} \, \mathbf{a}_{3}$ = $- a x_{14} \,\mathbf{\hat{x}}+b y_{14} \,\mathbf{\hat{y}}- c z_{14} \,\mathbf{\hat{z}}$ (16r) Ge VII
$\mathbf{B_{44}}$ = $\left(x_{14} + y_{14}\right) \, \mathbf{a}_{1}+\left(x_{14} - y_{14}\right) \, \mathbf{a}_{2}- z_{14} \, \mathbf{a}_{3}$ = $a x_{14} \,\mathbf{\hat{x}}- b y_{14} \,\mathbf{\hat{y}}- c z_{14} \,\mathbf{\hat{z}}$ (16r) Ge VII
$\mathbf{B_{45}}$ = $- \left(x_{14} - y_{14}\right) \, \mathbf{a}_{1}- \left(x_{14} + y_{14}\right) \, \mathbf{a}_{2}- z_{14} \, \mathbf{a}_{3}$ = $- a x_{14} \,\mathbf{\hat{x}}- b y_{14} \,\mathbf{\hat{y}}- c z_{14} \,\mathbf{\hat{z}}$ (16r) Ge VII
$\mathbf{B_{46}}$ = $\left(x_{14} - y_{14}\right) \, \mathbf{a}_{1}+\left(x_{14} + y_{14}\right) \, \mathbf{a}_{2}- z_{14} \, \mathbf{a}_{3}$ = $a x_{14} \,\mathbf{\hat{x}}+b y_{14} \,\mathbf{\hat{y}}- c z_{14} \,\mathbf{\hat{z}}$ (16r) Ge VII
$\mathbf{B_{47}}$ = $\left(x_{14} + y_{14}\right) \, \mathbf{a}_{1}+\left(x_{14} - y_{14}\right) \, \mathbf{a}_{2}+z_{14} \, \mathbf{a}_{3}$ = $a x_{14} \,\mathbf{\hat{x}}- b y_{14} \,\mathbf{\hat{y}}+c z_{14} \,\mathbf{\hat{z}}$ (16r) Ge VII
$\mathbf{B_{48}}$ = $- \left(x_{14} + y_{14}\right) \, \mathbf{a}_{1}- \left(x_{14} - y_{14}\right) \, \mathbf{a}_{2}+z_{14} \, \mathbf{a}_{3}$ = $- a x_{14} \,\mathbf{\hat{x}}+b y_{14} \,\mathbf{\hat{y}}+c z_{14} \,\mathbf{\hat{z}}$ (16r) Ge VII

References

  • S. Ishida, Y. Yanagi, K. Oka, K. Kataoka, H. Fujihisa, H. Kito, Y. Yoshida, A. Iyo, I. Hase, Y. Gotoh, and H. Eisaki, Crystal Structure and Superconductivity of BaIr$_{2}$Ge$_{7}$ and Ba$_{3}$Ir$_{4}$Ge$_{16}$ with Two-Dimensional Ba-Ge Networks, J. Am. Chem. Soc. 136, 5245–5248 (2014), doi:10.1021/ja5011527.

Found in

  • C. Pei, T. Ying, Y. Zhao, L. Gao, W. Cao, C. Li, H. Hosono, and Y. Qi, Pressure-induced reemergence of superconductivity in BaIr$_{2}$Ge$_{7}$ and Ba$_{3}$Ir$_{4}$Ge$_{16}$ with cage structures, Matter Radiat. Extremes 7, 038404 (2022), doi:10.1063/5.0088235.

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=AB9C2_oC96_65_acg_ghoq3r_2g2h --params=$a,b/a,c/a,x_{3},x_{4},x_{5},x_{6},x_{7},x_{8},x_{9},x_{10},z_{10},x_{11},y_{11},x_{12},y_{12},z_{12},x_{13},y_{13},z_{13},x_{14},y_{14},z_{14}$

Species:

Running:

Output: