Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: AB2_oI12_74_e_2e-001

If you are using this page, please cite:
H. Eckert, S. Divilov, M. J. Mehl, D. Hicks, A. C. Zettel, M. Esters. X. Campilongo and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 4. Submitted to Computational Materials Science.

Links to this page

https://aflow.org/p/EQ3C
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GdSi$_{2}$ Structure: AB2_oI12_74_e_2e-001

Picture of Structure; Click for Big Picture
Prototype GdSi$_{2}$
AFLOW prototype label AB2_oI12_74_e_2e-001
ICSD 291182
Pearson symbol oI12
Space group number 74
Space group symbol $Imma$
AFLOW prototype command aflow --proto=AB2_oI12_74_e_2e-001
--params=$a, \allowbreak b/a, \allowbreak c/a, \allowbreak z_{1}, \allowbreak z_{2}, \allowbreak z_{3}$

Other compounds with this structure

GeSi$_{2}$,  HoSi$_{2}$,  LaGe$_{2}$,  TbSi$_{2}$,  DySi$_{1.4}$,  GdSi$_{1.4}$,  NdSi$_{1.4}$,  PrSi$_{1.4}$,  SmSi$_{1.4}$,  YSi$_{1.4}$


  • (Zou, 2015) find that the Si-I site has 96.8% occupancy and the Si-II site has 81.2% occupancy, so the actual stoichiometry of their sample is GdSi$_{1.78}$.

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

Basis vectors

Lattice coordinates Cartesian coordinates Wyckoff position Atom type
$\mathbf{B_{1}}$ = $\left(z_{1} + \frac{1}{4}\right) \, \mathbf{a}_{1}+z_{1} \, \mathbf{a}_{2}+\frac{1}{4} \, \mathbf{a}_{3}$ = $\frac{1}{4}b \,\mathbf{\hat{y}}+c z_{1} \,\mathbf{\hat{z}}$ (4e) Gd I
$\mathbf{B_{2}}$ = $- \left(z_{1} - \frac{3}{4}\right) \, \mathbf{a}_{1}- z_{1} \, \mathbf{a}_{2}+\frac{3}{4} \, \mathbf{a}_{3}$ = $\frac{3}{4}b \,\mathbf{\hat{y}}- c z_{1} \,\mathbf{\hat{z}}$ (4e) Gd I
$\mathbf{B_{3}}$ = $\left(z_{2} + \frac{1}{4}\right) \, \mathbf{a}_{1}+z_{2} \, \mathbf{a}_{2}+\frac{1}{4} \, \mathbf{a}_{3}$ = $\frac{1}{4}b \,\mathbf{\hat{y}}+c z_{2} \,\mathbf{\hat{z}}$ (4e) Si I
$\mathbf{B_{4}}$ = $- \left(z_{2} - \frac{3}{4}\right) \, \mathbf{a}_{1}- z_{2} \, \mathbf{a}_{2}+\frac{3}{4} \, \mathbf{a}_{3}$ = $\frac{3}{4}b \,\mathbf{\hat{y}}- c z_{2} \,\mathbf{\hat{z}}$ (4e) Si I
$\mathbf{B_{5}}$ = $\left(z_{3} + \frac{1}{4}\right) \, \mathbf{a}_{1}+z_{3} \, \mathbf{a}_{2}+\frac{1}{4} \, \mathbf{a}_{3}$ = $\frac{1}{4}b \,\mathbf{\hat{y}}+c z_{3} \,\mathbf{\hat{z}}$ (4e) Si II
$\mathbf{B_{6}}$ = $- \left(z_{3} - \frac{3}{4}\right) \, \mathbf{a}_{1}- z_{3} \, \mathbf{a}_{2}+\frac{3}{4} \, \mathbf{a}_{3}$ = $\frac{3}{4}b \,\mathbf{\hat{y}}- c z_{3} \,\mathbf{\hat{z}}$ (4e) Si II

References

  • J. D. Zou, J. Liu, and M. Yan, Crystal structure and magnetic properties of GdSi$_{1.78}$, Gd(Si$_{0.684}$Ge$_{0.316}$)$_{1.78}$, GdGe$_{1.57}$, and GdSn$_{2}$ compounds, J. Magn. Magn. Mater. 385, 77–82 (2015), doi:10.1016/j.jmmm.2015.02.057.
  • W. B. Pearson, A Handbook of Lattice Spacings and Structures of Metals and Alloys, Volume 2, International Series of Monographs on Metal Physics and Physical Metallurgy, vol. 8 (Pergamon Press, Oxford, London, Edinburgh, New York, Toronto, Sydney, Paris, Braunschweig, 1967).

Prototype Generator

aflow --proto=AB2_oI12_74_e_2e --params=$a,b/a,c/a,z_{1},z_{2},z_{3}$

Species:

Running:

Output: