NbAs Structure: AB_tI8_109_a_a-001
| Prototype | AsNb |
| AFLOW prototype label | AB_tI8_109_a_a-001 |
| ICSD | 16585 |
| Pearson symbol | tI8 |
| Space group number | 109 |
| Space group symbol | $I4_1md$ |
| AFLOW prototype command |
aflow --proto=AB_tI8_109_a_a-001
--params=$a, \allowbreak c/a, \allowbreak z_{1}, \allowbreak z_{2}$ |
Other compounds with this structure
TaAs, $\beta$-TaP, $\beta$-NbP
- Space group $I4_{1}md$ #109 allows an arbitary placement of the $z$-axis origin. Here we chose to place a niobium atom at the origin.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&- \frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{2}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{3}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}- \frac{1}{2}c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $z_{1} \, \mathbf{a}_{1}+z_{1} \, \mathbf{a}_{2}$ | = | $c z_{1} \,\mathbf{\hat{z}}$ | (4a) | As I |
| $\mathbf{B_{2}}$ | = | $\left(z_{1} + \frac{3}{4}\right) \, \mathbf{a}_{1}+\left(z_{1} + \frac{1}{4}\right) \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{y}}+c \left(z_{1} + \frac{1}{4}\right) \,\mathbf{\hat{z}}$ | (4a) | As I |
| $\mathbf{B_{3}}$ | = | $z_{2} \, \mathbf{a}_{1}+z_{2} \, \mathbf{a}_{2}$ | = | $c z_{2} \,\mathbf{\hat{z}}$ | (4a) | Nb I |
| $\mathbf{B_{4}}$ | = | $\left(z_{2} + \frac{3}{4}\right) \, \mathbf{a}_{1}+\left(z_{2} + \frac{1}{4}\right) \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{y}}+c \left(z_{2} + \frac{1}{4}\right) \,\mathbf{\hat{z}}$ | (4a) | Nb I |
References
- S. Furuseth and A. Kjekshus, On the Arsendies and Antimonides of Niobium, Acta Chem. Scand. 18, 1180–1195 (1964), doi:10.3891/acta.chem.scand.18-1180.
Found in
- P. Villars and K. Cenzual, Pearson's Crystal Data – Crystal Structure Database for Inorganic Compounds (2013). ASM International.
Prototype Generator
aflow --proto=AB_tI8_109_a_a --params=$a,c/a,z_{1},z_{2}$