LaOF Structure: ABC_tP6_129_a_c_b-001
Other compounds with this structure
DyOF, ErOF, EuOF, GdOF, HoOF, LiMnAs, LiMnP, LiMnSb, NdOF, PuOF, PrOF, SmOF, TbOF, YOF
- 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)
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&a \,\mathbf{\hat{x}}\\\mathbf{a_{2}}&=&a \,\mathbf{\hat{y}}\\\mathbf{a_{3}}&=&c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $\frac{3}{4} \, \mathbf{a}_{1}+\frac{1}{4} \, \mathbf{a}_{2}$ | = | $\frac{3}{4}a \,\mathbf{\hat{x}}+\frac{1}{4}a \,\mathbf{\hat{y}}$ | (2a) | F I |
| $\mathbf{B_{2}}$ | = | $\frac{1}{4} \, \mathbf{a}_{1}+\frac{3}{4} \, \mathbf{a}_{2}$ | = | $\frac{1}{4}a \,\mathbf{\hat{x}}+\frac{3}{4}a \,\mathbf{\hat{y}}$ | (2a) | F I |
| $\mathbf{B_{3}}$ | = | $\frac{3}{4} \, \mathbf{a}_{1}+\frac{1}{4} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{3}{4}a \,\mathbf{\hat{x}}+\frac{1}{4}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ | (2b) | O I |
| $\mathbf{B_{4}}$ | = | $\frac{1}{4} \, \mathbf{a}_{1}+\frac{3}{4} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{4}a \,\mathbf{\hat{x}}+\frac{3}{4}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ | (2b) | O I |
| $\mathbf{B_{5}}$ | = | $\frac{1}{4} \, \mathbf{a}_{1}+\frac{1}{4} \, \mathbf{a}_{2}+z_{3} \, \mathbf{a}_{3}$ | = | $\frac{1}{4}a \,\mathbf{\hat{x}}+\frac{1}{4}a \,\mathbf{\hat{y}}+c z_{3} \,\mathbf{\hat{z}}$ | (2c) | La I |
| $\mathbf{B_{6}}$ | = | $\frac{3}{4} \, \mathbf{a}_{1}+\frac{3}{4} \, \mathbf{a}_{2}- z_{3} \, \mathbf{a}_{3}$ | = | $\frac{3}{4}a \,\mathbf{\hat{x}}+\frac{3}{4}a \,\mathbf{\hat{y}}- c z_{3} \,\mathbf{\hat{z}}$ | (2c) | La 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.
First cited in
- H. Eckert, S. Divilov, M. J. Mehl, D. Hicks, A. C. Zettel, M. Esters, X. Campilongo, and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 4, Comp. Mat. Sci. 240, 112988 (2024). (doi=10.1016/j.commatsci.2021.110450)
Geometry files
Prototype Generator
aflow --proto=ABC_tP6_129_a_c_b --params=$a,c/a,z_{3}$