Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: A_mP4_4_2a

  • 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)

High–pressure Te Structure: A_mP4_4_2a

Picture of Structure; Click for Big Picture
Prototype : Te
AFLOW prototype label : A_mP4_4_2a
Strukturbericht designation : None
Pearson symbol : mP4
Space group number : 4
Space group symbol : $\text{P2}_{1}$
AFLOW prototype command : aflow --proto=A_mP4_4_2a
--params=
$a$,$b/a$,$c/a$,$\beta$,$x_{1}$,$y_{1}$,$z_{1}$,$x_{2}$,$y_{2}$,$z_{2}$


  • This is a high-pressure phase of Te, stable in the 4-7 GPa range. The ground state of Te appears to be $\gamma$–Se (A8).

Simple Monoclinic primitive vectors:

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

Basis vectors:

\[ \begin{array}{ccccccc} & & \text{Lattice Coordinates} & & \text{Cartesian Coordinates} &\text{Wyckoff Position} & \text{Atom Type} \\ \mathbf{B}_{1} & =& x_{1} \, \mathbf{a}_{1} + y_{1} \, \mathbf{a}_{2} + z_{1} \, \mathbf{a}_{3}& =& \left(x_{1} \, a + z_{1} \, c \, \cos\beta\right) \, \mathbf{\hat{x}}+ y_{1} \, b \, \mathbf{\hat{y}}+ z_{1} \, c \, \sin\beta \, \mathbf{\hat{z}}& \left(2a\right) & \text{Te I} \\ \mathbf{B}_{2} & =& - x_{1} \, \mathbf{a}_{1} + \left(\frac12 + y_{1}\right) \, \mathbf{a}_{2} - z_{1} \, \mathbf{a}_{3}& =& - \left(x_{1} \, a + z_{1} \, c \, \cos\beta\right) \, \mathbf{\hat{x}}+ \left(\frac12 + y_{1}\right) \, b \, \mathbf{\hat{y}}- z_{1} \, c \, \sin\beta \, \mathbf{\hat{z}}& \left(2a\right) & \text{Te I} \\ \mathbf{B}_{3} & =& x_{2} \, \mathbf{a}_{1} + y_{2} \, \mathbf{a}_{2} + z_{2} \, \mathbf{a}_{3}& =& \left(x_{2} \, a + z_{2} \, c \, \cos\beta\right) \, \mathbf{\hat{x}}+ y_{2} \, b \, \mathbf{\hat{y}}+ z_{2} \, c \, \sin\beta \, \mathbf{\hat{z}}& \left(2a\right) & \text{Te II} \\ \mathbf{B}_{4} & =& - x_{2} \, \mathbf{a}_{1} + \left(\frac12 + y_{2}\right) \, \mathbf{a}_{2} - z_{2} \, \mathbf{a}_{3}& =& - \left(x_{2} \, a + z_{2} \, c \, \cos\beta\right) \, \mathbf{\hat{x}}+ \left(\frac12 + y_{2}\right) \, b \, \mathbf{\hat{y}}- z_{2} \, c \, \sin\beta \, \mathbf{\hat{z}}& \left(2a\right) & \text{Te II} \\ \end{array} \]

References

  • K. Aoki, O. Shimomura, and S. Minomura, Crystal Structure of the High–Pressure Phase of Tellurium, J. Phys. Soc. Jpn. 48, 551–556 (1980), doi:10.1143/JPSJ.48.551.

Geometry files


Prototype Generator

aflow --proto=A_mP4_4_2a --params=

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