CeAuAl$_{4}$Ge$_{2}$ Structure: A4BCD2_hR8_166_2c_a_b_c-001

Picture of Structure; Click for Big Picture
Prototype Al$_{4}$AuCeGe$_{2}$
AFLOW prototype label A4BCD2_hR8_166_2c_a_b_c-001
ICSD 415287
CCDC 1729371
Pearson symbol hR8
Space group number 166
Space group symbol $R\overline{3}m$
AFLOW prototype command aflow --proto=A4BCD2_hR8_166_2c_a_b_c-001
--params=$a, \allowbreak c/a, \allowbreak x_{3}, \allowbreak x_{4}, \allowbreak x_{5}$

Other compounds with this structure

CeAuAl$_{4}$Ge$_{2}$,  CePtAl$_{4}$Ge$_{2}$,  DyAuAl$_{4}$Ge$_{2}$,  ErAuAl$_{4}$Ge$_{2}$,  EuAuAl$_{4}$Ge$_{2}$,  GdAuAl$_{4}$Ge$_{2}$,  GdNiAl$_{4}$Ge$_{2}$,  LuNiAl$_{4}$Ge$_{2}$,  NdAuAl$_{4}$Ge$_{2}$,  PrAuAl$_{4}$Ge$_{2}$,  SmAuAl$_{4}$Ge$_{2}$,  TbAuAl$_{4}$Ge$_{2}$,  TmAuAl$_{4}$Ge$_{2}$,  YNiAl$_{4}$Ge$_{2}$


  • Like EuAuAl$_{4}$(Au$_{1-x}$Ge$_{x}$)$_{2}$, the rare earth atoms in this structure have a complex antiferromagnetic ordering at low temperatures (Feng, 2024).
  • 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
$\mathbf{B_{1}}$ = $0$ = $0$ (1a) Au I
$\mathbf{B_{2}}$ = $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}c \,\mathbf{\hat{z}}$ (1b) Ce I
$\mathbf{B_{3}}$ = $x_{3} \, \mathbf{a}_{1}+x_{3} \, \mathbf{a}_{2}+x_{3} \, \mathbf{a}_{3}$ = $c x_{3} \,\mathbf{\hat{z}}$ (2c) Al I
$\mathbf{B_{4}}$ = $- x_{3} \, \mathbf{a}_{1}- x_{3} \, \mathbf{a}_{2}- x_{3} \, \mathbf{a}_{3}$ = $- c x_{3} \,\mathbf{\hat{z}}$ (2c) Al I
$\mathbf{B_{5}}$ = $x_{4} \, \mathbf{a}_{1}+x_{4} \, \mathbf{a}_{2}+x_{4} \, \mathbf{a}_{3}$ = $c x_{4} \,\mathbf{\hat{z}}$ (2c) Al II
$\mathbf{B_{6}}$ = $- x_{4} \, \mathbf{a}_{1}- x_{4} \, \mathbf{a}_{2}- x_{4} \, \mathbf{a}_{3}$ = $- c x_{4} \,\mathbf{\hat{z}}$ (2c) Al II
$\mathbf{B_{7}}$ = $x_{5} \, \mathbf{a}_{1}+x_{5} \, \mathbf{a}_{2}+x_{5} \, \mathbf{a}_{3}$ = $c x_{5} \,\mathbf{\hat{z}}$ (2c) Ge I
$\mathbf{B_{8}}$ = $- x_{5} \, \mathbf{a}_{1}- x_{5} \, \mathbf{a}_{2}- x_{5} \, \mathbf{a}_{3}$ = $- c x_{5} \,\mathbf{\hat{z}}$ (2c) Ge I

References

  • X. Wu and M. G. Kanatzidis, REAuAl$_{4}$Ge$_{2}$ and REAuAl$_{4}$(Au$_{x}$Ge$_{1-x}$)$_{2}$ (RE=rare earth element): Quaternary intermetallics grown in liquid aluminum, J. Solid State Chem. 178, 3233–3242 (2005), doi:10.1103/PhysRevB.109.014436.

Found in

  • K. Feng, C. Bush, O. Oladehin, M. Lee, and R. Baumbach, Complex antiferromagnetic order in the metallic triangular lattice compound SmAuAl$_{4}$Ge$_{2}$, Phys. Rev. B 109, 014436 (2024), doi:10.1103/PhysRevB.109.014436.

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=A4BCD2_hR8_166_2c_a_b_c --params=$a,c/a,x_{3},x_{4},x_{5}$

Species:

Running:

Output: