Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: A_hR2_166_c-003

This structure originally had the label A_hR2_166_c.beta-O. Calls to that address will be redirected here.

If you are using this page, please cite:
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)

Links to this page

https://aflow.org/p/KTH0
or https://aflow.org/p/A_hR2_166_c-003
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β-O$_{2}$ Structure: A_hR2_166_c-003

Picture of Structure; Click for Big Picture
Prototype O
AFLOW prototype label A_hR2_166_c-003
ICSD 173934
Pearson symbol hR2
Space group number 166
Space group symbol $R\overline{3}m$
AFLOW prototype command aflow --proto=A_hR2_166_c-003
--params=$a, \allowbreak c/a, \allowbreak x_{1}$

  • $\alpha$–As ($A7$), rhombohedral graphite, and $\beta$–O have the same AFLOW prototype label, A_hR2_166_c. They are generated by the same symmetry operations with different sets of parameters (--params) specified in their corresponding CIF files. Hexagonal settings of rhombohedral structures can be obtained with the option --hex.

\[ \begin{array}{ccc} \mathbf{a_{1}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}\\\mathbf{a_{2}}&=&\frac{1}{\sqrt{3}}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}\\\mathbf{a_{3}}&=&- \frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}} \end{array}\]

Basis vectors

Lattice coordinates Cartesian coordinates Wyckoff position Atom type
$\mathbf{B_{1}}$ = $x_{1} \, \mathbf{a}_{1}+x_{1} \, \mathbf{a}_{2}+x_{1} \, \mathbf{a}_{3}$ = $c x_{1} \,\mathbf{\hat{z}}$ (2c) O I
$\mathbf{B_{2}}$ = $- x_{1} \, \mathbf{a}_{1}- x_{1} \, \mathbf{a}_{2}- x_{1} \, \mathbf{a}_{3}$ = $- c x_{1} \,\mathbf{\hat{z}}$ (2c) O I

References

  • R. J. Meier and R. B. Helmholdt, Neutron-diffraction study of α- and β-oxygen, Phys. Rev. B 29, 1387–1393 (1984), doi:10.1103/PhysRevB.29.1387.

Prototype Generator

aflow --proto=A_hR2_166_c --params=$a,c/a,x_{1}$

Species:

Running:

Output: