Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: A2B_hP9_189_fg_ad-001

This structure originally had the label A2B_hP9_189_fg_bc. Calls to that address will be redirected here.

If you are using this page, please cite:
M. J. Mehl, D. Hicks, C. Toher, O. Levy, R. M. Hanson, G. L. W. Hart, and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 1, Comp. Mat. Sci. 136, S1-S828 (2017). (doi=10.1016/j.commatsci.2017.01.017)

Links to this page

https://aflow.org/p/6UK2
or https://aflow.org/p/A2B_hP9_189_fg_ad-001
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Barringerite (Revised Fe$_{2}$P, $C22$) Crystal Structure: A2B_hP9_189_fg_ad-001

Picture of Structure; Click for Big Picture
Prototype Fe$_{2}$P
AFLOW prototype label A2B_hP9_189_fg_ad-001
Strukturbericht designation $C22$
Mineral name barringerite
ICSD 200529
Pearson symbol hP9
Space group number 189
Space group symbol $P\overline{6}2m$
AFLOW prototype command aflow --proto=A2B_hP9_189_fg_ad-001
--params=$a, \allowbreak c/a, \allowbreak x_{3}, \allowbreak x_{4}$

Other compounds with this structure

Co$_{2}$As,  Mg$_{2}$In,  Mn$_{2}$P,  Ni$_{2}$P,  Pd$_{2}$As,  Pd$_{2}$Ge,  Pd$_{2}$Si,  Pt$_{2}$Ge,  Pt$_{2}$Si (HT)


  • This is not the structure given in (Hermann, 1937) Strukturbericht Vol. II, 95. As noted by (Wyckoff, 1963), that structure was generally accepted for years, [but] has recently been shown to be incorrect. This is the corrected structure, as given in Wyckoff and (Villars, 1991). See the original Fe$_{2}$P ($C22$) page for the Strukturbericht version of this crystal.
  • This is the binary version of the structure. The two iron sites are independent, and can be replaced by different atoms. We put the resulting ternary structures under the ZrNiAl prototype.

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

Basis vectors

Lattice coordinates Cartesian coordinates Wyckoff position Atom type
$\mathbf{B_{1}}$ = $0$ = $0$ (1a) P I
$\mathbf{B_{2}}$ = $\frac{1}{3} \, \mathbf{a}_{1}+\frac{2}{3} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (2d) P II
$\mathbf{B_{3}}$ = $\frac{2}{3} \, \mathbf{a}_{1}+\frac{1}{3} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (2d) P II
$\mathbf{B_{4}}$ = $x_{3} \, \mathbf{a}_{1}$ = $\frac{1}{2}a x_{3} \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{2}a x_{3} \,\mathbf{\hat{y}}$ (3f) Fe I
$\mathbf{B_{5}}$ = $x_{3} \, \mathbf{a}_{2}$ = $\frac{1}{2}a x_{3} \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{2}a x_{3} \,\mathbf{\hat{y}}$ (3f) Fe I
$\mathbf{B_{6}}$ = $- x_{3} \, \mathbf{a}_{1}- x_{3} \, \mathbf{a}_{2}$ = $- a x_{3} \,\mathbf{\hat{x}}$ (3f) Fe I
$\mathbf{B_{7}}$ = $x_{4} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}a x_{4} \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{2}a x_{4} \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (3g) Fe II
$\mathbf{B_{8}}$ = $x_{4} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}a x_{4} \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{2}a x_{4} \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (3g) Fe II
$\mathbf{B_{9}}$ = $- x_{4} \, \mathbf{a}_{1}- x_{4} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $- a x_{4} \,\mathbf{\hat{x}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (3g) Fe II

References

  • H. Fujii, S. Komura, T. Takeda, T. Okamoto, Y. Ito, and J. Akimitsu, Polarized Neutron Diffraction Study of Fe$_2$P Single Crystal, J. Phys. Soc. Jpn. 46, 1616–1621 (1979), doi:10.1143/JPSJ.46.1616.
  • C. Hermann, O. Lohrmann, and H. Philipp, eds., Strukturbericht Band II 1928-1932 (Akademische Verlagsgesellschaft M. B. H., Leipzig, 1937).
  • P. Villars and L. Calvert, Pearson's Handbook of Crystallographic Data for Intermetallic Phases (ASM International, Materials Park, OH, 1991), 2nd edn.

Found in

  • R. G. W. Wyckoff, Crystal Structure, vol. 1 (Interscience, New York, London, Sydney, 1963).

Prototype Generator

aflow --proto=A2B_hP9_189_fg_ad --params=$a,c/a,x_{3},x_{4}$

Species:

Running:

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