Revised Fe2P ($C22$) Crystal Structure: A2B_hP9_189_fg_bc

Picture of Structure; Click for Big Picture
Prototype : Fe2P
AFLOW prototype label : A2B_hP9_189_fg_bc
Strukturbericht designation : $C22$
Pearson symbol : hP9
Space group number : 189
Space group symbol : $\mbox{P}\bar{6}\mbox{2m}$
AFLOW prototype command : aflow --proto=A2B_hP9_189_fg_bc
--params=
$a$,$c/a$,$x_{3}$,$x_{4}$


Other compounds with this structure

  • AgAsCa, AgSiYb, AlCoPu, AlCuTm, AlNiTb, FeNiP, FeGaU, Mn2P, Ni2P, Ni6Si2B, Pt2Si, RhSnZr, hundreds more

  • This is not the structure given in (Hermann, 1937) Strukturbericht Vol. II, 95. As noted by (Wyckoff, 1963) 360, the structure which was generally accepted for years, has recently been shown to be incorrect. This is the corrected structure, as given in Wyckoff and (Villars, 1991). See the original Fe2P (C22) page for the Strukturbericht version of this crystal.

Hexagonal primitive vectors:

\[ \begin{array}{ccc} \mathbf{a}_1 & = & \frac12 \, a \, \mathbf{\hat{x}} - \frac{\sqrt{3}}{2} \, a \, \mathbf{\hat{y}} \\ \mathbf{a}_2 & = & \frac12 \, a \, \mathbf{\hat{x}} + \frac{\sqrt{3}}{2} \, a \, \mathbf{\hat{y}} \\ \mathbf{a}_3 & = & c \, \mathbf{\hat{z}}\\ \end{array} \]

Basis vectors:

\[ \begin{array}{ccccccc} & & \mbox{Lattice Coordinates} & & \mbox{Cartesian Coordinates} &\mbox{Wyckoff Position} & \mbox{Atom Type} \\ \mathbf{B}_{1}& = &\frac12 \, \mathbf{a}_{3}& = &\frac12 \, c \, \mathbf{\hat{z}}& \left(1b\right) & \mbox{P I} \\ \mathbf{B}_{2}& = &\frac13 \, \mathbf{a}_{1}+ \frac23 \, \mathbf{a}_{2}& = &\frac12 \, a \, \mathbf{\hat{x}}+ \frac1{2\sqrt3} \, a \, \mathbf{\hat{y}}& \left(2c\right) & \mbox{P II} \\ \mathbf{B}_{3}& = &\frac23 \, \mathbf{a}_{1}+ \frac13 \, \mathbf{a}_{2}& = &\frac12 \, a \, \mathbf{\hat{x}}- \frac1{2\sqrt3} \, a \, \mathbf{\hat{y}}& \left(2c\right) & \mbox{P II} \\ \mathbf{B}_{4}& = &x_{3} \, \mathbf{a}_{1}& = &\frac12 \, x_{3} \, a \, \mathbf{\hat{x}}- \frac{\sqrt3}{2} \, x_{3} \, a \, \mathbf{\hat{y}}& \left(3f\right) & \mbox{Fe I} \\ \mathbf{B}_{5}& = &x_{3} \, \mathbf{a}_{2}& = &\frac12 \, x_{3} \, a \, \mathbf{\hat{x}}+ \frac{\sqrt3}{2} \, x_{3} \, a \, \mathbf{\hat{y}}& \left(3f\right) & \mbox{Fe I} \\ \mathbf{B}_{6}& = &- x_{3} \, \mathbf{a}_{1}- x_{3} \, \mathbf{a}_{2}& = &- x_{3} \, a \, \mathbf{\hat{x}}& \left(3f\right) & \mbox{Fe I} \\ \mathbf{B}_{7}& = &x_{4} \, \mathbf{a}_{1}+ \frac12 \, \mathbf{a}_{3}& = &\frac12 \, x_{4} \, a \, \mathbf{\hat{x}}- \frac{\sqrt3}{2} \, x_{4} \, a \, \mathbf{\hat{y}}+ \frac12 \, c \, \mathbf{\hat{z}}& \left(3g\right) & \mbox{Fe II} \\ \mathbf{B}_{8}& = &x_{4} \, \mathbf{a}_{2}+ \frac12 \, \mathbf{a}_{3}& = &\frac12 \, x_{4} \, a \, \mathbf{\hat{x}}+ \frac{\sqrt3}{2} \, x_{4} \, a \, \mathbf{\hat{y}}+ \frac12 \, c \, \mathbf{\hat{z}}& \left(3g\right) & \mbox{Fe II} \\ \mathbf{B}_{9}& = &- x_{4} \, \mathbf{a}_{1}- x_{4} \, \mathbf{a}_{2}+ \frac12 \, \mathbf{a}_{3}& = &- x_{4} \, a \, \mathbf{\hat{x}}+ \frac12 \, c \, \mathbf{\hat{z}}& \left(3g\right) & \mbox{Fe II} \\ \end{array} \]

References

  • H. Fujii, S. Komura, T. Takeda, T. Okamoto, Y. Ito, and J. Akimitsu, Polarized Neutron Diffraction Study of Fe2P Single Crystal, J. Phys. Soc. Jpn. 46, 1616–1621 (1979), doi:10.1143/JPSJ.46.1616.
  • C. Hermann, O. Lohrmann, and H. Philipp, Strukturbericht Band II, 1928–1932 (Akademsiche 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. W. G. Wyckoff, Crystal Structures Vol. 1 (Wiley, 1963), 2nd edn., pp. 360.

Geometry files


Prototype Generator

aflow --proto=A2B_hP9_189_fg_bc --params=

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