Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: A2B_hP9_150_ef_bd

  • 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)
  • D. Hicks, M. J. Mehl, E. Gossett, C. Toher, O. Levy, R. M. Hanson, G. L. W. Hart, and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 2, Comp. Mat. Sci. 161, S1-S1011 (2019). (doi=10.1016/j.commatsci.2018.10.043)
  • D. Hicks, M.J. Mehl, M. Esters, C. Oses, O. Levy, G.L.W. Hart, C. Toher, and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 3, Comp. Mat. Sci. 199, 110450 (2021). (doi=10.1016/j.commatsci.2021.110450)

Original Fe2P ($C22$) Structure: A2B_hP9_150_ef_bd

Picture of Structure; Click for Big Picture
Prototype : Fe2P
AFLOW prototype label : A2B_hP9_150_ef_bd
Strukturbericht designation : $C22$
Pearson symbol : hP9
Space group number : 150
Space group symbol : $\text{P321}$
AFLOW prototype command : aflow --proto=A2B_hP9_150_ef_bd
--params=
$a$,$c/a$,$z_{2}$,$x_{3}$,$x_{4}$


  • This is the structure given in Strukturbericht Vol. II. As noted by Wyckoff, the structure, which was generally accepted for years, has recently been shown to be incorrect. (Vol I., 360) This corrected structure, as given in Pearson's Handbook, is given in the revised Fe2P page. When $z_{2}$ is set to zero this structure reverts to the revised Fe2P structure.

Trigonal 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:

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

References

  • S. B. Hendricks and P. R. Kosting, The Crystal Structure of Fe2P, Fe2N, Fe3N and FeB, Zeitschrift für Kristallographie – Crystalline Materials 74, 511–533 (1930), doi:10.1524/zkri.1930.74.1.511.
  • R. W. G. Wyckoff, Crystal Structures Vol. 2, Inorganic Compounds RXn, RnMX2, RnMX3 (Wiley, 1964), 2nd edn.
  • P. Villars and L. Calvert, Pearson's Handbook of Crystallographic Data for Intermetallic Phases (ASM International, Materials Park, OH, 1991), 2nd edn.

Found in

  • C. Hermann, O. Lohrmann, and H. Philipp, Strukturbericht Band II, 1928–1932 (Akademsiche Verlagsgesellschaft M. B. H., Leipzig, 1937)., pp. 15.

Geometry files


Prototype Generator

aflow --proto=A2B_hP9_150_ef_bd --params=

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