HgBa$_{2}$CaCu$_{2}$O$_{6+\delta}$ Structure: A2BC2DE7_tP13_123_g_b_h_c_ahi-001
| Prototype | Ba$_{2}$CaCu$_{2}$HgO$_{7}$ |
| AFLOW prototype label | A2BC2DE7_tP13_123_g_b_h_c_ahi-001 |
| ICSD | 74142 |
| Pearson symbol | tP13 |
| Space group number | 123 |
| Space group symbol | $P4/mmm$ |
| AFLOW prototype command |
aflow --proto=A2BC2DE7_tP13_123_g_b_h_c_ahi-001
--params=$a, \allowbreak c/a, \allowbreak z_{4}, \allowbreak z_{5}, \allowbreak z_{6}, \allowbreak z_{7}$ |
Other compounds with this structure
TlBa$_{2}$CaCu$_{2}$O$_{6+\delta}$
- We use the data of (Huang, 1993) taken at 10K.
- The O-I (1c) site, in the layer with the mercury atoms, is fractionally occupied, with $\delta = 0.219$ for the present sample.
- (Huang, 1993) refer to the (2i) Wyckoff position for the O-III site, but this should be (4i).
- (Villars, 2016) give TlBa$_{2}$CaCu$_{2}$O$_{6+\delta}$ as the prototype for this system, but we can find no information for that structure, even in that reference.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&a \,\mathbf{\hat{x}}\\\mathbf{a_{2}}&=&a \,\mathbf{\hat{y}}\\\mathbf{a_{3}}&=&c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $0$ | = | $0$ | (1a) | O I |
| $\mathbf{B_{2}}$ | = | $\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}c \,\mathbf{\hat{z}}$ | (1b) | Ca I |
| $\mathbf{B_{3}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}$ | (1c) | Hg I |
| $\mathbf{B_{4}}$ | = | $z_{4} \, \mathbf{a}_{3}$ | = | $c z_{4} \,\mathbf{\hat{z}}$ | (2g) | Ba I |
| $\mathbf{B_{5}}$ | = | $- z_{4} \, \mathbf{a}_{3}$ | = | $- c z_{4} \,\mathbf{\hat{z}}$ | (2g) | Ba I |
| $\mathbf{B_{6}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+z_{5} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+c z_{5} \,\mathbf{\hat{z}}$ | (2h) | Cu I |
| $\mathbf{B_{7}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}- z_{5} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}- c z_{5} \,\mathbf{\hat{z}}$ | (2h) | Cu I |
| $\mathbf{B_{8}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+z_{6} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+c z_{6} \,\mathbf{\hat{z}}$ | (2h) | O II |
| $\mathbf{B_{9}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}- z_{6} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}- c z_{6} \,\mathbf{\hat{z}}$ | (2h) | O II |
| $\mathbf{B_{10}}$ | = | $\frac{1}{2} \, \mathbf{a}_{2}+z_{7} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{y}}+c z_{7} \,\mathbf{\hat{z}}$ | (4i) | O III |
| $\mathbf{B_{11}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+z_{7} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+c z_{7} \,\mathbf{\hat{z}}$ | (4i) | O III |
| $\mathbf{B_{12}}$ | = | $\frac{1}{2} \, \mathbf{a}_{2}- z_{7} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{y}}- c z_{7} \,\mathbf{\hat{z}}$ | (4i) | O III |
| $\mathbf{B_{13}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}- z_{7} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}- c z_{7} \,\mathbf{\hat{z}}$ | (4i) | O III |
References
- Q. Huang, J. W. Lynn, R. L. Meng, and C. W. Chu, Crystal structure of annealed and as-prepared HgBa$_{2}$CaCu$_{2}$O$_{6+\delta}$ superconductors, Physica C 218, 356–364 (1993), doi:10.1016/0921-4534(93)90036-P.
- Ba2CaCu2HgO6.2 Crystal Structure: Datasheet from
PAULING FILE Multinaries Edition – 2012
in SpringerMaterials. Copyright 2016 Springer-Verlag Berlin Heidelberg and Material Phases Data System (MPDS), Switzerland, and National Institute for Materials Science (NIMS), Japan.
Prototype Generator
aflow --proto=A2BC2DE7_tP13_123_g_b_h_c_ahi --params=$a,c/a,z_{4},z_{5},z_{6},z_{7}$