Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: A2B_oC12_36_2a_a

  • 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)

HgBr2 ($C24$) Structure: A2B_oC12_36_2a_a

Picture of Structure; Click for Big Picture
Prototype : HgBr2
AFLOW prototype label : A2B_oC12_36_2a_a
Strukturbericht designation : $C24$
Pearson symbol : oC12
Space group number : 36
Space group symbol : $\text{Cmc2}_{1}$
AFLOW prototype command : aflow --proto=A2B_oC12_36_2a_a
--params=
$a$,$b/a$,$c/a$,$y_{1}$,$z_{1}$,$y_{2}$,$z_{2}$,$y_{3}$,$z_{3}$


Base-centered Orthorhombic primitive vectors:

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

Basis vectors:

\[ \begin{array}{ccccccc} & & \text{Lattice Coordinates} & & \text{Cartesian Coordinates} &\text{Wyckoff Position} & \text{Atom Type} \\ \mathbf{B}_{1} & =& - y_{1} \, \mathbf{a}_{1} + y_{1} \, \mathbf{a}_{2} + z_{1} \, \mathbf{a}_{3}& =& y_{1} \, b \, \mathbf{\hat{y}} + z_{1} \, c \mathbf{\hat{z}}& \left(4a\right) & \text{Br I} \\ \mathbf{B}_{2} & =& y_{1} \, \mathbf{a}_{1} - y_{1} \, \mathbf{a}_{2} + \left(\frac12 + z_{1}\right) \, \mathbf{a}_{3}& =& - y_{1} \, b \, \mathbf{\hat{y}} + \left(\frac12 + z_{1}\right) \, c \mathbf{\hat{z}}& \left(4a\right) & \text{Br I} \\ \mathbf{B}_{3} & =& - y_{2} \, \mathbf{a}_{1} + y_{2} \, \mathbf{a}_{2} + z_{2} \, \mathbf{a}_{3}& =& y_{2} \, b \, \mathbf{\hat{y}} + z_{2} \, c \mathbf{\hat{z}}& \left(4a\right) & \text{Br II} \\ \mathbf{B}_{4} & =& y_{2} \, \mathbf{a}_{1} - y_{2} \, \mathbf{a}_{2} + \left(\frac12 + z_{2}\right) \, \mathbf{a}_{3}& =& - y_{2} \, b \, \mathbf{\hat{y}} + \left(\frac12 + z_{2}\right) \, c \mathbf{\hat{z}}& \left(4a\right) & \text{Br II} \\ \mathbf{B}_{5} & =& - y_{3} \, \mathbf{a}_{1} + y_{3} \, \mathbf{a}_{2} + z_{3} \, \mathbf{a}_{3}& =& y_{3} \, b \, \mathbf{\hat{y}} + z_{3} \, c \mathbf{\hat{z}}& \left(4a\right) & \text{Hg} \\ \mathbf{B}_{6} & =& y_{3} \, \mathbf{a}_{1} - y_{3} \, \mathbf{a}_{2} + \left(\frac12 + z_{3}\right) \, \mathbf{a}_{3}& =& - y_{3} \, b \, \mathbf{\hat{y}} + \left(\frac12 + z_{3}\right) \, c \mathbf{\hat{z}}& \left(4a\right) & \text{Hg} \\ \end{array} \]

References

  • H. Braekken, Zur Kristallstruktur des Quecksilberbromids HgBr2, Zeitschrift für Kristallographie – Crystalline Materials 81, 152–154 (1932), doi:10.1524/zkri.1932.81.1.152.

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=A2B_oC12_36_2a_a --params=

Species:

Running:

Output: