AlCCr$_{2}$ Structure: ABC2_hP8_194_c_a_f-007
| Prototype | AlCCr$_{2}$ |
| AFLOW prototype label | ABC2_hP8_194_c_a_f-007 |
| ICSD | 42918 |
| Pearson symbol | hP8 |
| Space group number | 194 |
| Space group symbol | $P6_3/mmc$ |
| AFLOW prototype command |
aflow --proto=ABC2_hP8_194_c_a_f-007
--params=$a, \allowbreak c/a, \allowbreak z_{3}$ |
Other compounds with this structure
AlCNb$_{2}$, AlCTa$_{2}$, AlCTi$_{2}$, AlCV$_{2}$, AlCuO$_{2}$, AlNTi$_{2}$, AsCV$_{2}$, CCdTi$_{2}$, CGaCr$_{2}$, CGaMo$_{2}$, CGaNb$_{2}$, CGaTi$_{2}$, CGaY$_{2}$, CGeCr$_{2}$, CGeTi$_{2}$, CGeV$_{2}$, CInHf$_{2}$, CInNb$_{2}$, CInTi$_{2}$, CInZr$_{2}$, CPNb$_{2}$, CPV$_{2}$, CPbHf$_{2}$, CPbTi$_{2}$, CPbZr$_{2}$, CSTi$_{2}$, CSZr$_{2}$, CSnHf$_{2}$, CSnNb$_{2}$, CSnTi$_{2}$, CSnZr$_{2}$, CTlHf$_{2}$, CTlTi$_{2}$, GaNCr$_{2}$
- Note that all of the atoms sit on close-packed $<$$0001$$>$ planes. The stacking sequence may be written
Atom Cr C Cr Al Cr C Cr Al Position B A C B C A B C
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{2}a \,\mathbf{\hat{y}}\\\mathbf{a_{2}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{2}a \,\mathbf{\hat{y}}\\\mathbf{a_{3}}&=&c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $0$ | = | $0$ | (2a) | C I |
| $\mathbf{B_{2}}$ | = | $\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}c \,\mathbf{\hat{z}}$ | (2a) | C I |
| $\mathbf{B_{3}}$ | = | $\frac{1}{3} \, \mathbf{a}_{1}+\frac{2}{3} \, \mathbf{a}_{2}+\frac{1}{4} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{4}c \,\mathbf{\hat{z}}$ | (2c) | Al I |
| $\mathbf{B_{4}}$ | = | $\frac{2}{3} \, \mathbf{a}_{1}+\frac{1}{3} \, \mathbf{a}_{2}+\frac{3}{4} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{3}{4}c \,\mathbf{\hat{z}}$ | (2c) | Al I |
| $\mathbf{B_{5}}$ | = | $\frac{1}{3} \, \mathbf{a}_{1}+\frac{2}{3} \, \mathbf{a}_{2}+z_{3} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+c z_{3} \,\mathbf{\hat{z}}$ | (4f) | Cr I |
| $\mathbf{B_{6}}$ | = | $\frac{2}{3} \, \mathbf{a}_{1}+\frac{1}{3} \, \mathbf{a}_{2}+\left(z_{3} + \frac{1}{2}\right) \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+c \left(z_{3} + \frac{1}{2}\right) \,\mathbf{\hat{z}}$ | (4f) | Cr I |
| $\mathbf{B_{7}}$ | = | $\frac{2}{3} \, \mathbf{a}_{1}+\frac{1}{3} \, \mathbf{a}_{2}- z_{3} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}- c z_{3} \,\mathbf{\hat{z}}$ | (4f) | Cr I |
| $\mathbf{B_{8}}$ | = | $\frac{1}{3} \, \mathbf{a}_{1}+\frac{2}{3} \, \mathbf{a}_{2}- \left(z_{3} - \frac{1}{2}\right) \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}- c \left(z_{3} - \frac{1}{2}\right) \,\mathbf{\hat{z}}$ | (4f) | Cr I |
References
- W. Jeitschko, H. Nowotny, and F. Benesovsky, Kohlenstoffhaltige ternäre Verbindungen (H-Phase), Monatsh. Chem. Verw. Tl. 94, 672–676 (1963), doi:10.1007/BF00913068.
Found in
- P. Villars and L. Calvert, Pearson's Handbook of Crystallographic Data for Intermetallic Phases (ASM International, Materials Park, OH, 1991), 2nd edn.
Prototype Generator
aflow --proto=ABC2_hP8_194_c_a_f --params=$a,c/a,z_{3}$