$\beta$–O Structure: A_hR2_166_c
| Prototype | : | $\beta$–O |
| AFLOW prototype label | : | A_hR2_166_c |
| Strukturbericht designation | : | None |
| Pearson symbol | : | hR2 |
| Space group number | : | 166 |
| Space group symbol | : | $\mbox{R}\bar{3}\mbox{m}$ |
| AFLOW prototype command | : | aflow --proto=A_hR2_166_c [--hex] --params=$a,c/a,x_{1}$ |
- Note that $\alpha$–As (A_hR2_166_c, $\alpha$–As), rhombohedral graphite (A_hR2_166_c, C), and $\beta$–O (A_hR2_166_c, $\beta$–O) have the same AFLOW prototype label. They are generated by the same symmetry operations with different sets of parameters (––params) specified in their corresponding CIF files. Hexagonal settings of this structure can be obtained with the option ––hex.
Rhombohedral primitive vectors:
\[
\begin{array}{ccc}
\mathbf{a}_1 & = & ~ \frac12 \, a \, \mathbf{\hat{x}} - \frac{1}{2\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13
\, c \, \mathbf{\hat{z}} \\
\mathbf{a}_2 & = & \frac{1}{\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13 \, c \, \mathbf{\hat{z}} \\
\mathbf{a}_3 & = & - \frac12 \, a \, \mathbf{\hat{x}} - \frac{1}{2\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13
\, c \, \mathbf{\hat{z}} \\
\end{array}
\]
Basis vectors:
\[ \begin{array}{ccccccc} & & \mbox{Lattice Coordinates} & & \mbox{Cartesian Coordinates} &\mbox{Wyckoff Position} & \mbox{Atom Type} \\ \mathbf{B}_{1} & =&x_{1} \, \mathbf{a}_{1}+ x_{1} \, \mathbf{a}_{2}+ x_{1} \, \mathbf{a}_{3}& =&x_{1} \, c \, \mathbf{\hat{z}}& \left(2c\right) & \mbox{O} \\ \mathbf{B}_{2} & =&- x_{1} \, \mathbf{a}_{1}- x_{1} \, \mathbf{a}_{2}- x_{1} \, \mathbf{a}_{3}& =&- x_{1} \, c \, \mathbf{\hat{z}}& \left(2c\right) & \mbox{O} \\ \end{array} \]References
- R. J. Meier and R. B. Helmholdt, Neutron–diffraction study of alpha– and beta–oxygen, Phys. Rev. B 29, 1387–1393 (1984), doi:10.1103/PhysRevB.29.1387.