K$_{2}$NiF$_{4}$ Structure: A4B2C_tI14_139_ce_e_a-001
| Prototype | F$_{4}$K$_{2}$Ni |
| AFLOW prototype label | A4B2C_tI14_139_ce_e_a-001 |
| ICSD | 15576 |
| Pearson symbol | tI14 |
| Space group number | 139 |
| Space group symbol | $I4/mmm$ |
| AFLOW prototype command |
aflow --proto=A4B2C_tI14_139_ce_e_a-001
--params=$a, \allowbreak c/a, \allowbreak z_{3}, \allowbreak z_{4}$ |
Other compounds with this structure
Ba$_{2}$SnO$_{4}$, Ca$_{2}$MnO$_{4}$, Cs$_{2}$CrCl$_{4}$, Cs$_{2}$CrF$_{4}$, Cs$_{2}$CuCl$_{4}$, Cs$_{2}$CuF$_{4}$, K$_{2}$CrCl$_{4}$, K$_{2}$CrF$_{4}$, K$_{2}$CuCl$_{4}$, K$_{2}$CuF$_{4}$, La$_{2}$NiO$_{4}$, La$_{2}$PdO$_{4}$, Nd$_{2}$CuO$_{4}$, Sr$_{2}$IrO$_{4}$, Sr$_{2}$MnO$_{4}$, Sr$_{2}$RuO$_{4}$, Sr$_{2}$SnO$_{4}$, Sr$_{2}$TiO$_{4}$, Sr$_{2}$VO$_{4}$, (Fe, La)$_{2}$SrO$_{4}$, (Sr, La)$_{2}$AlO$_{4}$, (Sr, La)$_{2}$CoO$_{4}$
- This is the parent compound of the simplest layered-perovskite Ruddlesden-Popper series (Wikipedia). The series also includes the parent of the high-$T_{c}$ cuprates, (La,Ba)$_{2}$CuO$_{4}$, but we keep that separate as it represents a new class of materials.
- Sr$_{2}$CuO$_{2}$Cl$_{2}$ is the quaternary form of this structure.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&- \frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{2}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{3}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}- \frac{1}{2}c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $0$ | = | $0$ | (2a) | Ni I |
| $\mathbf{B_{2}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{y}}$ | (4c) | F I |
| $\mathbf{B_{3}}$ | = | $\frac{1}{2} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}$ | (4c) | F I |
| $\mathbf{B_{4}}$ | = | $z_{3} \, \mathbf{a}_{1}+z_{3} \, \mathbf{a}_{2}$ | = | $c z_{3} \,\mathbf{\hat{z}}$ | (4e) | F II |
| $\mathbf{B_{5}}$ | = | $- z_{3} \, \mathbf{a}_{1}- z_{3} \, \mathbf{a}_{2}$ | = | $- c z_{3} \,\mathbf{\hat{z}}$ | (4e) | F II |
| $\mathbf{B_{6}}$ | = | $z_{4} \, \mathbf{a}_{1}+z_{4} \, \mathbf{a}_{2}$ | = | $c z_{4} \,\mathbf{\hat{z}}$ | (4e) | K I |
| $\mathbf{B_{7}}$ | = | $- z_{4} \, \mathbf{a}_{1}- z_{4} \, \mathbf{a}_{2}$ | = | $- c z_{4} \,\mathbf{\hat{z}}$ | (4e) | K I |
References
- D. Balz and K. Pleith, Die Struktur des Kaliumnickelfluorids, K$_{2}$NiF$_{4}$, Z. Elektrochemie 59, 545–551 (1955).
Found in
- S. N. Ruddlesden and P. Popper, New compounds of the K$_{2}$NiF$_{4}$ type, Acta Cryst. 10, 538–539 (1957), doi:10.1107/S0365110X57001929.
Prototype Generator
aflow --proto=A4B2C_tI14_139_ce_e_a --params=$a,c/a,z_{3},z_{4}$