Archerite (KH2PO4) Structure : A2BC4D_oF64_43_b_a_2b_a

Picture of Structure; Click for Big Picture
Prototype : H2KO4P
AFLOW prototype label : A2BC4D_oF64_43_b_a_2b_a
Strukturbericht designation : None
Pearson symbol : oF64
Space group number : 43
Space group symbol : $Fdd2$
AFLOW prototype command : aflow --proto=A2BC4D_oF64_43_b_a_2b_a
--params=
$a$,$b/a$,$c/a$,$z_{1}$,$z_{2}$,$x_{3}$,$y_{3}$,$z_{3}$,$x_{4}$,$y_{4}$,$z_{4}$,$x_{5}$,$y_{5}$,$z_{5}$


  • This structure is stable below 121 K, and the data was taken at 113 K. The high temperature structure is tetragonal with disordered hydrogen. (Levy, 1954)
  • The origin of the $z$–axis is not restricted in space group $Fdd2$ #43. Here it is fixed by putting the phosphorous atom at the origin.

Face-centered Orthorhombic primitive vectors:

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

Basis vectors:

\[ \begin{array}{ccccccc} & & \mbox{Lattice Coordinates} & & \mbox{Cartesian Coordinates} &\mbox{Wyckoff Position} & \mbox{Atom Type} \\ \mathbf{B}_{1} & = & z_{1} \, \mathbf{a}_{1} + z_{1} \, \mathbf{a}_{2}-z_{1} \, \mathbf{a}_{3} & = & z_{1}c \, \mathbf{\hat{z}} & \left(8a\right) & \mbox{K} \\ \mathbf{B}_{2} & = & \left(\frac{1}{4} +z_{1}\right) \, \mathbf{a}_{1} + \left(\frac{1}{4} +z_{1}\right) \, \mathbf{a}_{2} + \left(\frac{1}{4} - z_{1}\right) \, \mathbf{a}_{3} & = & \frac{1}{4}a \, \mathbf{\hat{x}} + \frac{1}{4}b \, \mathbf{\hat{y}} + \left(\frac{1}{4} +z_{1}\right)c \, \mathbf{\hat{z}} & \left(8a\right) & \mbox{K} \\ \mathbf{B}_{3} & = & z_{2} \, \mathbf{a}_{1} + z_{2} \, \mathbf{a}_{2}-z_{2} \, \mathbf{a}_{3} & = & z_{2}c \, \mathbf{\hat{z}} & \left(8a\right) & \mbox{P} \\ \mathbf{B}_{4} & = & \left(\frac{1}{4} +z_{2}\right) \, \mathbf{a}_{1} + \left(\frac{1}{4} +z_{2}\right) \, \mathbf{a}_{2} + \left(\frac{1}{4} - z_{2}\right) \, \mathbf{a}_{3} & = & \frac{1}{4}a \, \mathbf{\hat{x}} + \frac{1}{4}b \, \mathbf{\hat{y}} + \left(\frac{1}{4} +z_{2}\right)c \, \mathbf{\hat{z}} & \left(8a\right) & \mbox{P} \\ \mathbf{B}_{5} & = & \left(-x_{3}+y_{3}+z_{3}\right) \, \mathbf{a}_{1} + \left(x_{3}-y_{3}+z_{3}\right) \, \mathbf{a}_{2} + \left(x_{3}+y_{3}-z_{3}\right) \, \mathbf{a}_{3} & = & x_{3}a \, \mathbf{\hat{x}} + y_{3}b \, \mathbf{\hat{y}} + z_{3}c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{H} \\ \mathbf{B}_{6} & = & \left(x_{3}-y_{3}+z_{3}\right) \, \mathbf{a}_{1} + \left(-x_{3}+y_{3}+z_{3}\right) \, \mathbf{a}_{2} + \left(-x_{3}-y_{3}-z_{3}\right) \, \mathbf{a}_{3} & = & -x_{3}a \, \mathbf{\hat{x}}-y_{3}b \, \mathbf{\hat{y}} + z_{3}c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{H} \\ \mathbf{B}_{7} & = & \left(\frac{1}{4} - x_{3} - y_{3} + z_{3}\right) \, \mathbf{a}_{1} + \left(\frac{1}{4} +x_{3} + y_{3} + z_{3}\right) \, \mathbf{a}_{2} + \left(\frac{1}{4} +x_{3} - y_{3} - z_{3}\right) \, \mathbf{a}_{3} & = & \left(\frac{1}{4} +x_{3}\right)a \, \mathbf{\hat{x}} + \left(\frac{1}{4}-y_{3}\right)b \, \mathbf{\hat{y}} + \left(\frac{1}{4} +z_{3}\right)c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{H} \\ \mathbf{B}_{8} & = & \left(\frac{1}{4} +x_{3} + y_{3} + z_{3}\right) \, \mathbf{a}_{1} + \left(\frac{1}{4} - x_{3} - y_{3} + z_{3}\right) \, \mathbf{a}_{2} + \left(\frac{1}{4} - x_{3} + y_{3} - z_{3}\right) \, \mathbf{a}_{3} & = & \left(\frac{1}{4}-x_{3}\right)a \, \mathbf{\hat{x}} + \left(\frac{1}{4} +y_{3}\right)b \, \mathbf{\hat{y}} + \left(\frac{1}{4} +z_{3}\right)c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{H} \\ \mathbf{B}_{9} & = & \left(-x_{4}+y_{4}+z_{4}\right) \, \mathbf{a}_{1} + \left(x_{4}-y_{4}+z_{4}\right) \, \mathbf{a}_{2} + \left(x_{4}+y_{4}-z_{4}\right) \, \mathbf{a}_{3} & = & x_{4}a \, \mathbf{\hat{x}} + y_{4}b \, \mathbf{\hat{y}} + z_{4}c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{O I} \\ \mathbf{B}_{10} & = & \left(x_{4}-y_{4}+z_{4}\right) \, \mathbf{a}_{1} + \left(-x_{4}+y_{4}+z_{4}\right) \, \mathbf{a}_{2} + \left(-x_{4}-y_{4}-z_{4}\right) \, \mathbf{a}_{3} & = & -x_{4}a \, \mathbf{\hat{x}}-y_{4}b \, \mathbf{\hat{y}} + z_{4}c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{O I} \\ \mathbf{B}_{11} & = & \left(\frac{1}{4} - x_{4} - y_{4} + z_{4}\right) \, \mathbf{a}_{1} + \left(\frac{1}{4} +x_{4} + y_{4} + z_{4}\right) \, \mathbf{a}_{2} + \left(\frac{1}{4} +x_{4} - y_{4} - z_{4}\right) \, \mathbf{a}_{3} & = & \left(\frac{1}{4} +x_{4}\right)a \, \mathbf{\hat{x}} + \left(\frac{1}{4}-y_{4}\right)b \, \mathbf{\hat{y}} + \left(\frac{1}{4} +z_{4}\right)c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{O I} \\ \mathbf{B}_{12} & = & \left(\frac{1}{4} +x_{4} + y_{4} + z_{4}\right) \, \mathbf{a}_{1} + \left(\frac{1}{4} - x_{4} - y_{4} + z_{4}\right) \, \mathbf{a}_{2} + \left(\frac{1}{4} - x_{4} + y_{4} - z_{4}\right) \, \mathbf{a}_{3} & = & \left(\frac{1}{4}-x_{4}\right)a \, \mathbf{\hat{x}} + \left(\frac{1}{4} +y_{4}\right)b \, \mathbf{\hat{y}} + \left(\frac{1}{4} +z_{4}\right)c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{O I} \\ \mathbf{B}_{13} & = & \left(-x_{5}+y_{5}+z_{5}\right) \, \mathbf{a}_{1} + \left(x_{5}-y_{5}+z_{5}\right) \, \mathbf{a}_{2} + \left(x_{5}+y_{5}-z_{5}\right) \, \mathbf{a}_{3} & = & x_{5}a \, \mathbf{\hat{x}} + y_{5}b \, \mathbf{\hat{y}} + z_{5}c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{O II} \\ \mathbf{B}_{14} & = & \left(x_{5}-y_{5}+z_{5}\right) \, \mathbf{a}_{1} + \left(-x_{5}+y_{5}+z_{5}\right) \, \mathbf{a}_{2} + \left(-x_{5}-y_{5}-z_{5}\right) \, \mathbf{a}_{3} & = & -x_{5}a \, \mathbf{\hat{x}}-y_{5}b \, \mathbf{\hat{y}} + z_{5}c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{O II} \\ \mathbf{B}_{15} & = & \left(\frac{1}{4} - x_{5} - y_{5} + z_{5}\right) \, \mathbf{a}_{1} + \left(\frac{1}{4} +x_{5} + y_{5} + z_{5}\right) \, \mathbf{a}_{2} + \left(\frac{1}{4} +x_{5} - y_{5} - z_{5}\right) \, \mathbf{a}_{3} & = & \left(\frac{1}{4} +x_{5}\right)a \, \mathbf{\hat{x}} + \left(\frac{1}{4}-y_{5}\right)b \, \mathbf{\hat{y}} + \left(\frac{1}{4} +z_{5}\right)c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{O II} \\ \mathbf{B}_{16} & = & \left(\frac{1}{4} +x_{5} + y_{5} + z_{5}\right) \, \mathbf{a}_{1} + \left(\frac{1}{4} - x_{5} - y_{5} + z_{5}\right) \, \mathbf{a}_{2} + \left(\frac{1}{4} - x_{5} + y_{5} - z_{5}\right) \, \mathbf{a}_{3} & = & \left(\frac{1}{4}-x_{5}\right)a \, \mathbf{\hat{x}} + \left(\frac{1}{4} +y_{5}\right)b \, \mathbf{\hat{y}} + \left(\frac{1}{4} +z_{5}\right)c \, \mathbf{\hat{z}} & \left(16b\right) & \mbox{O II} \\ \end{array} \]

References

  • H. A. Levy, S. W. Peterson, and S. H. Simonsen, Neutron Diffraction Study of the Ferroelectric Modification of Potassium Dihydrogen Phosphate, Phys. Rev. 93, 1120–1121 (1954), doi:10.1103/PhysRev.93.1120.

Found in

  • R. T. Downs and M. Hall–Wallace, The American Mineralogist Crystal Structure Database, Am. Mineral. 88, 247–250 (2003).

Geometry files


Prototype Generator

aflow --proto=A2BC4D_oF64_43_b_a_2b_a --params=

Species:

Running:

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