Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: AB_oP12_51_ei_fj-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.

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https://aflow.org/p/1M54
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TaRh Structure: AB_oP12_51_ei_fj-001

Picture of Structure; Click for Big Picture
Prototype RhTa
AFLOW prototype label AB_oP12_51_ei_fj-001
ICSD 105938
Pearson symbol oP12
Space group number 51
Space group symbol $Pmma$
AFLOW prototype command aflow --proto=AB_oP12_51_ei_fj-001
--params=$a, \allowbreak b/a, \allowbreak c/a, \allowbreak z_{1}, \allowbreak z_{2}, \allowbreak x_{3}, \allowbreak z_{3}, \allowbreak x_{4}, \allowbreak z_{4}$

Other compounds with this structure

NbIr,  TaIr,  NbRh


  • (Giessen, 1964) give the actual composition as (Ta$_{0.79}$Rh$_{0.21}$)Rh, with similar compositions for the related compounds.
  • (Pearson, 1967) and others refer to this as $\alpha_{1}$-TaRh.
  • (Giessen, 1964) give the structure in the $Pmcm$ setting of space group #51. We used FINDSYM to transform this to the standard $Pmma$ setting.

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

Basis vectors

Lattice coordinates Cartesian coordinates Wyckoff position Atom type
$\mathbf{B_{1}}$ = $\frac{1}{4} \, \mathbf{a}_{1}+z_{1} \, \mathbf{a}_{3}$ = $\frac{1}{4}a \,\mathbf{\hat{x}}+c z_{1} \,\mathbf{\hat{z}}$ (2e) Rh I
$\mathbf{B_{2}}$ = $\frac{3}{4} \, \mathbf{a}_{1}- z_{1} \, \mathbf{a}_{3}$ = $\frac{3}{4}a \,\mathbf{\hat{x}}- c z_{1} \,\mathbf{\hat{z}}$ (2e) Rh I
$\mathbf{B_{3}}$ = $\frac{1}{4} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+z_{2} \, \mathbf{a}_{3}$ = $\frac{1}{4}a \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}+c z_{2} \,\mathbf{\hat{z}}$ (2f) Ta I
$\mathbf{B_{4}}$ = $\frac{3}{4} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}- z_{2} \, \mathbf{a}_{3}$ = $\frac{3}{4}a \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}- c z_{2} \,\mathbf{\hat{z}}$ (2f) Ta I
$\mathbf{B_{5}}$ = $x_{3} \, \mathbf{a}_{1}+z_{3} \, \mathbf{a}_{3}$ = $a x_{3} \,\mathbf{\hat{x}}+c z_{3} \,\mathbf{\hat{z}}$ (4i) Rh II
$\mathbf{B_{6}}$ = $- \left(x_{3} - \frac{1}{2}\right) \, \mathbf{a}_{1}+z_{3} \, \mathbf{a}_{3}$ = $- a \left(x_{3} - \frac{1}{2}\right) \,\mathbf{\hat{x}}+c z_{3} \,\mathbf{\hat{z}}$ (4i) Rh II
$\mathbf{B_{7}}$ = $- x_{3} \, \mathbf{a}_{1}- z_{3} \, \mathbf{a}_{3}$ = $- a x_{3} \,\mathbf{\hat{x}}- c z_{3} \,\mathbf{\hat{z}}$ (4i) Rh II
$\mathbf{B_{8}}$ = $\left(x_{3} + \frac{1}{2}\right) \, \mathbf{a}_{1}- z_{3} \, \mathbf{a}_{3}$ = $a \left(x_{3} + \frac{1}{2}\right) \,\mathbf{\hat{x}}- c z_{3} \,\mathbf{\hat{z}}$ (4i) Rh II
$\mathbf{B_{9}}$ = $x_{4} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+z_{4} \, \mathbf{a}_{3}$ = $a x_{4} \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}+c z_{4} \,\mathbf{\hat{z}}$ (4j) Ta II
$\mathbf{B_{10}}$ = $- \left(x_{4} - \frac{1}{2}\right) \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+z_{4} \, \mathbf{a}_{3}$ = $- a \left(x_{4} - \frac{1}{2}\right) \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}+c z_{4} \,\mathbf{\hat{z}}$ (4j) Ta II
$\mathbf{B_{11}}$ = $- x_{4} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}- z_{4} \, \mathbf{a}_{3}$ = $- a x_{4} \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}- c z_{4} \,\mathbf{\hat{z}}$ (4j) Ta II
$\mathbf{B_{12}}$ = $\left(x_{4} + \frac{1}{2}\right) \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}- z_{4} \, \mathbf{a}_{3}$ = $a \left(x_{4} + \frac{1}{2}\right) \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}- c z_{4} \,\mathbf{\hat{z}}$ (4j) Ta II

References

  • B. C. Giessen and N. J. Grant, New intermediate phases in system of Nb or Ta with Rh, Ir, Pd, or Pt, Acta Cryst. 17, 615–616 (1964), doi:10.1107/S0365110X64001438.

Found in

  • 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=AB_oP12_51_ei_fj --params=$a,b/a,c/a,z_{1},z_{2},x_{3},z_{3},x_{4},z_{4}$

Species:

Running:

Output: