$F5_{4}$ (NH$_{4}$ClO$_{2}$) (Obsolete) Structure: ABC2_tP8_100_b_a_c-001
| Prototype | Cl(NH$_{4}$)O$_{2}$ |
| AFLOW prototype label | ABC2_tP8_100_b_a_c-001 |
| Strukturbericht designation | $F5_{4}$ |
| ICSD | 36179 |
| Pearson symbol | tP8 |
| Space group number | 100 |
| Space group symbol | $P4bm$ |
| AFLOW prototype command |
aflow --proto=ABC2_tP8_100_b_a_c-001
--params=$a, \allowbreak c/a, \allowbreak z_{1}, \allowbreak z_{2}, \allowbreak x_{3}, \allowbreak z_{3}$ |
- (Levi, 1931) first determined this structure, but they were actually looking at a combination of ammonium chlorite, NH$_{4}$ClO$_{2}$ and ammonium chlorate, NH$_{4}$ClO$_{3}$, which takes on the $\gamma$–KNO$_{3}$ structure. In addition, they were unable to determine the positions of the hydrogen atoms, and it appears that space group $P4bm$ #100 is incompatible with having four hydrogen atoms in a tetrahedral arrangement about the nitrogen atom. (Smolentsev, 2005) determined the positions of the hydrogen atoms, and placed this structure in space group $P\overline{4}2_{1}m$ #113, making the structure of (Levi, 1931) obsolete. We present it here for historical interest.
- Since the position of the hydrogen atoms in the NH$_{4}$ ions were not determined, we only provide the nitrogen atom positions (labeled as NH$_{4}$).
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&a \,\mathbf{\hat{x}}\\\mathbf{a_{2}}&=&a \,\mathbf{\hat{y}}\\\mathbf{a_{3}}&=&c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $z_{1} \, \mathbf{a}_{3}$ | = | $c z_{1} \,\mathbf{\hat{z}}$ | (2a) | NH I |
| $\mathbf{B_{2}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+z_{1} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+c z_{1} \,\mathbf{\hat{z}}$ | (2a) | NH I |
| $\mathbf{B_{3}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+z_{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+c z_{2} \,\mathbf{\hat{z}}$ | (2b) | Cl I |
| $\mathbf{B_{4}}$ | = | $\frac{1}{2} \, \mathbf{a}_{2}+z_{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{y}}+c z_{2} \,\mathbf{\hat{z}}$ | (2b) | Cl I |
| $\mathbf{B_{5}}$ | = | $x_{3} \, \mathbf{a}_{1}+\left(x_{3} + \frac{1}{2}\right) \, \mathbf{a}_{2}+z_{3} \, \mathbf{a}_{3}$ | = | $a x_{3} \,\mathbf{\hat{x}}+a \left(x_{3} + \frac{1}{2}\right) \,\mathbf{\hat{y}}+c z_{3} \,\mathbf{\hat{z}}$ | (4c) | O I |
| $\mathbf{B_{6}}$ | = | $- x_{3} \, \mathbf{a}_{1}- \left(x_{3} - \frac{1}{2}\right) \, \mathbf{a}_{2}+z_{3} \, \mathbf{a}_{3}$ | = | $- a x_{3} \,\mathbf{\hat{x}}- a \left(x_{3} - \frac{1}{2}\right) \,\mathbf{\hat{y}}+c z_{3} \,\mathbf{\hat{z}}$ | (4c) | O I |
| $\mathbf{B_{7}}$ | = | $- \left(x_{3} - \frac{1}{2}\right) \, \mathbf{a}_{1}+x_{3} \, \mathbf{a}_{2}+z_{3} \, \mathbf{a}_{3}$ | = | $- a \left(x_{3} - \frac{1}{2}\right) \,\mathbf{\hat{x}}+a x_{3} \,\mathbf{\hat{y}}+c z_{3} \,\mathbf{\hat{z}}$ | (4c) | O I |
| $\mathbf{B_{8}}$ | = | $\left(x_{3} + \frac{1}{2}\right) \, \mathbf{a}_{1}- x_{3} \, \mathbf{a}_{2}+z_{3} \, \mathbf{a}_{3}$ | = | $a \left(x_{3} + \frac{1}{2}\right) \,\mathbf{\hat{x}}- a x_{3} \,\mathbf{\hat{y}}+c z_{3} \,\mathbf{\hat{z}}$ | (4c) | O I |
References
- G. R. Levi and A. Scherillo, Ricerche cristallografiche sui sali dell'acido cloroso, Z. Kristallogr. 76, 431–452 (1931), doi:10.1524/zkri.1931.76.1.431.
- A. I. Smolentsev and D. Y. Naumov, Ammonium chlorite, NH$_{4}$ClO$_{2}$, at 150 K, Acta Crystallogr. Sect. E 61, i38–i40 (2005), doi:10.1107/S1600536805005088.
Found in
- C. Hermann, O. Lohrmann, and H. Philipp, eds., Strukturbericht Band II 1928-1932 (Akademische Verlagsgesellschaft M. B. H., Leipzig, 1937).
Prototype Generator
aflow --proto=ABC2_tP8_100_b_a_c --params=$a,c/a,z_{1},z_{2},x_{3},z_{3}$