K2NiF4 Structure : A4B2C_tI14_139_ce_e_a
| Prototype | : | F4K2Ni |
| AFLOW prototype label | : | A4B2C_tI14_139_ce_e_a |
| Strukturbericht designation | : | None |
| Pearson symbol | : | tI14 |
| Space group number | : | 139 |
| Space group symbol | : | $I4/mmm$ |
| AFLOW prototype command | : | aflow --proto=A4B2C_tI14_139_ce_e_a --params=$a$,$c/a$,$z_{3}$,$z_{4}$ |
Other compounds with this structure
- Ca2MnO4, La2PdO4, Nd2CuO4, Sr2MnO4, Sr2RuO4, Sr2TiO4, Sr2VO4, (Fe,La)2SrO4, (Sr,La)2AlO4, and (Sr,La)2CoO4
- This is the parent compound of the simplest layered–perovskite Ruddlesden–Popper series (Wikipedia). The series also includes the parent of the high–$T_{\mathrm{c}}$ cuprates, (La,Ba)2CuO4, but we keep that separate as it represents a new class of materials.
Body-centered Tetragonal primitive vectors:
\[
\begin{array}{ccc}
\mathbf{a}_1 & = & - \frac12 \, a \, \mathbf{\hat{x}} + \frac12 \, a \, \mathbf{\hat{y}} + \frac12 \, c \, \mathbf{\hat{z}} \\
\mathbf{a}_2 & = & ~ \frac12 \, a \, \mathbf{\hat{x}} - \frac12 \, a \, \mathbf{\hat{y}} + \frac12 \, c \, \mathbf{\hat{z}} \\
\mathbf{a}_3 & = & ~ \frac12 \, a \, \mathbf{\hat{x}} + \frac12 \, a \, \mathbf{\hat{y}} - \frac12 \, c \, \mathbf{\hat{z}} \\
\end{array}
\]
Basis vectors:
\[ \begin{array}{ccccccc} & & \text{Lattice Coordinates} & & \text{Cartesian Coordinates} &\text{Wyckoff Position} & \text{Atom Type} \\ \mathbf{B}_{1} & = & 0 \, \mathbf{a}_{1} + 0 \, \mathbf{a}_{2} + 0 \, \mathbf{a}_{3} & = & 0 \, \mathbf{\hat{x}} + 0 \, \mathbf{\hat{y}} + 0 \, \mathbf{\hat{z}} & \left(2a\right) & \text{Ni} \\ \mathbf{B}_{2} & = & \frac{1}{2} \, \mathbf{a}_{1} + \frac{1}{2} \, \mathbf{a}_{3} & = & \frac{1}{2}a \, \mathbf{\hat{y}} & \left(4c\right) & \text{F I} \\ \mathbf{B}_{3} & = & \frac{1}{2} \, \mathbf{a}_{2} + \frac{1}{2} \, \mathbf{a}_{3} & = & \frac{1}{2}a \, \mathbf{\hat{x}} & \left(4c\right) & \text{F I} \\ \mathbf{B}_{4} & = & z_{3} \, \mathbf{a}_{1} + z_{3} \, \mathbf{a}_{2} & = & z_{3}c \, \mathbf{\hat{z}} & \left(4e\right) & \text{F II} \\ \mathbf{B}_{5} & = & -z_{3} \, \mathbf{a}_{1}-z_{3} \, \mathbf{a}_{2} & = & -z_{3}c \, \mathbf{\hat{z}} & \left(4e\right) & \text{F II} \\ \mathbf{B}_{6} & = & z_{4} \, \mathbf{a}_{1} + z_{4} \, \mathbf{a}_{2} & = & z_{4}c \, \mathbf{\hat{z}} & \left(4e\right) & \text{K} \\ \mathbf{B}_{7} & = & -z_{4} \, \mathbf{a}_{1}-z_{4} \, \mathbf{a}_{2} & = & -z_{4}c \, \mathbf{\hat{z}} & \left(4e\right) & \text{K} \\ \end{array} \]References
- S. N. Ruddlesden and P. Popper, New compounds of the K2NiF4 type, Acta Cryst. 10, 538–539 (1957), doi:10.1107/S0365110X57001929.
Found in
- Wikipedia, Ruddlesden–Popper phase, https://en.wikipedia.org/wiki/Ruddlesden–Popper_phase. A3B2X7 series.