NiAs ($B8_{1}$) Structure: AB_hP4_194_c_a
| Prototype | : | NiAs |
| AFLOW prototype label | : | AB_hP4_194_c_a |
| Strukturbericht designation | : | $B8_{1}$ |
| Pearson symbol | : | hP4 |
| Space group number | : | 194 |
| Space group symbol | : | $\text{P6}_{3}\text{/mmc}$ |
| AFLOW prototype command | : | aflow --proto=AB_hP4_194_c_a --params=$a$,$c/a$ |
Other compounds with this structure
- AuSn, CoTe, CrSe, CuSn, FeS, IrS, MnAs, NiSn, PdSb, PtB, RhSn, VP, ZrTe
- Note that the stacking is ABACABAC, with the Ni atoms on the A sites and As on B and C. The environment of the Ni atoms is fcc-like, and the environment of the As atoms is hcp-like.
Hexagonal primitive vectors:
\[ \begin{array}{ccc} \mathbf{a}_1 & = & \frac12 \, a \, \mathbf{\hat{x}} - \frac{\sqrt3}2 \, a \, \mathbf{\hat{y}} \\ \mathbf{a}_2 & = & \frac12 \, a \, \mathbf{\hat{x}} + \frac{\sqrt3}2 \, a \, \mathbf{\hat{y}} \\ \mathbf{a}_3 & = & c \, \mathbf{\hat{z}}\\ \end{array} \]
Basis vectors:
\[ \begin{array}{ccccccc} & & \text{Lattice Coordinates} & & \text{Cartesian Coordinates} &\text{Wyckoff Position} & \text{Atom Type} \\ \mathbf{B}_{1}& = &0 \, \mathbf{a}_{1} + 0 \, \mathbf{a}_{2} + 0 \, \mathbf{a}_{3} & = &0 \mathbf{\hat{x}} + 0 \mathbf{\hat{y}} + 0 \mathbf{\hat{z}} & \left(2a\right) & \text{Ni} \\ \mathbf{B}_{2}& = &\frac12 \, \mathbf{a}_{3}& = &\frac12 \, c \, \mathbf{\hat{z}}& \left(2a\right) & \text{Ni} \\ \mathbf{B}_{3}& = &\frac13 \, \mathbf{a}_{1}+ \frac23 \, \mathbf{a}_{2}+ \frac14 \, \mathbf{a}_{3}& = &\frac12 \, a \, \mathbf{\hat{x}}+ \frac{1}{2\sqrt{3}} \, a \, \mathbf{\hat{y}}+ \frac14 \, c \, \mathbf{\hat{z}}& \left(2c\right) & \text{As} \\ \mathbf{B}_{4}& = &\frac23 \, \mathbf{a}_{1}+ \frac13 \, \mathbf{a}_{2}+ \frac34 \, \mathbf{a}_{3}& = &\frac12 \, a \, \mathbf{\hat{x}}- \frac{1}{2\sqrt{3}} \, a \, \mathbf{\hat{y}}+ \frac34 \, c \, \mathbf{\hat{z}}& \left(2c\right) & \text{As} \\ \end{array} \]References
- P. Brand and J. Briest, Das quasi–binäre System NiAs–Ni1.5Sn, Z. Anorg. Allg. Chem. 337, 209–213 (1965), doi:10.1002/zaac.19653370314.
Found in
- P. Villars and L. Calvert, Pearson's Handbook of Crystallographic Data for Intermetallic Phases (ASM International, Materials Park, OH, 1991), 2nd edn., pp. 1192.