YOF Structure: ABC_hR6_166_c_c_c-002
| Prototype | FOY |
| AFLOW prototype label | ABC_hR6_166_c_c_c-002 |
| ICSD | 30623 |
| Pearson symbol | hR6 |
| Space group number | 166 |
| Space group symbol | $R\overline{3}m$ |
| AFLOW prototype command |
aflow --proto=ABC_hR6_166_c_c_c-002
--params=$a, \allowbreak c/a, \allowbreak x_{1}, \allowbreak x_{2}, \allowbreak x_{3}$ |
Other compounds with this structure
DyOF, ErOF, EuOF, GdOF, HoOF, LaOF, NdOF, PrOF, SmOF, TbOF
- The general formula for this compound is XO$_{x}$F$_{3-2x}$. For $x \le 1$ the structure is tetragonal (LaOF prototype), and when $x > 1$ it is rhombohedral (YOF prototype). At high temperatures these structures transform into the cubic fluorite ($C1$) structure, with the anions statistically distributed over the (2c) sites. (Zachariasen, 1951; Petzel, 1993)
- SmSI and YOF have the same AFLOW prototype label, ABC_hR6_166_c_c_c. 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.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}\\\mathbf{a_{2}}&=&\frac{1}{\sqrt{3}}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}\\\mathbf{a_{3}}&=&- \frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}
\end{array}\]
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) | F 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) | F I |
| $\mathbf{B_{3}}$ | = | $x_{2} \, \mathbf{a}_{1}+x_{2} \, \mathbf{a}_{2}+x_{2} \, \mathbf{a}_{3}$ | = | $c x_{2} \,\mathbf{\hat{z}}$ | (2c) | O I |
| $\mathbf{B_{4}}$ | = | $- x_{2} \, \mathbf{a}_{1}- x_{2} \, \mathbf{a}_{2}- x_{2} \, \mathbf{a}_{3}$ | = | $- c x_{2} \,\mathbf{\hat{z}}$ | (2c) | O I |
| $\mathbf{B_{5}}$ | = | $x_{3} \, \mathbf{a}_{1}+x_{3} \, \mathbf{a}_{2}+x_{3} \, \mathbf{a}_{3}$ | = | $c x_{3} \,\mathbf{\hat{z}}$ | (2c) | Y I |
| $\mathbf{B_{6}}$ | = | $- x_{3} \, \mathbf{a}_{1}- x_{3} \, \mathbf{a}_{2}- x_{3} \, \mathbf{a}_{3}$ | = | $- c x_{3} \,\mathbf{\hat{z}}$ | (2c) | Y I |
References
- W. H. Zachariasen, Crystal chemical studies of the 5f-series of elements. XIV. Oxyfluorides, XOF, Acta Cryst. 4, 231–236 (1951), doi:10.1107/S0365110X51000787.
- T. Petzel, V. Marx, and B. Hormann, Thermodynamics of the rhombohedral-cubic phase transition of ROF with R $\equiv$ Y, La, Pr, Nd, Sm-Er, J. Alloys Compd. 200, 27–31 (1993), doi:10.1016/0925-8388(93)90466-Z.
Found in
- J. W. Fergus, Crystal structure of lanthanum oxyfluoride, J. Mater. Sci. Lett. 16, 267–269 (1997), doi:10.1023/A:1018584614532.
Prototype Generator
aflow --proto=ABC_hR6_166_c_c_c --params=$a,c/a,x_{1},x_{2},x_{3}$