NaNbO$_{3}$ $P4/mbm$ Lueshite Perovskite Structure: ABC3_tP10_127_c_a_bg-001
Other compounds with this structure
AgTaO$_{3}$, CsDyBr$_{3}$, CuKF$_{3}$, NaMgF$_{3}$, NaTaO$_{3}$, SrNbO$_{3}$
- As with most perovskites, NaNbO$_{3}$ (Lueshite) exists in a variety of forms depending on temperature and composition. Many of these phases are identified in (Mitchell, 2014). There is no consistent naming scheme that we are aware of, so we list the structures by space group. All the structure are identified in (Mitchell, 2014) unless otherwise noted. The paper does not give phase boundaries, so we will only indicate the temperatures at which the measurements were made.
- Synthetic Lueshite in orthorhombic space group $Pbcm$ #57.
- (Mitchell, 2014) find naturally occurring Lueshite in the $Pnma$ CaTiO$_{3}$ phase.
- (Vousden, 1951) found a ferroelectric Lueshite in space group $P222_{1}$ #17.
- At 575 and 600$^\circ$C Lueshite is in the base-centered orthorhombic space group $Cmcm$ #63.
- At 625$^\circ$C, Lueshite is in the orthorhombic space group $P4/mbm$ #127. (this structure)
- At 650 and 675$^\circ$C, and presumably at higher temperatures, NaNbO$_{3}$ is in the cubic perovskite ($E2_{1}$) structure.
- We use the data taken at 625$^\circ$C.
- The similar structures are listed in the form ABC$_{3}$, where the
A
species are on the (2c) sites, theB
species on the (2a) site, and theC
species on the (2b), and (4g) sites. The A and B sites are often alloyed.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&a \,\mathbf{\hat{x}}\\\mathbf{a_{2}}&=&a \,\mathbf{\hat{y}}\\\mathbf{a_{3}}&=&c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $0$ | = | $0$ | (2a) | Nb I |
| $\mathbf{B_{2}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}$ | (2a) | Nb I |
| $\mathbf{B_{3}}$ | = | $\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}c \,\mathbf{\hat{z}}$ | (2b) | O I |
| $\mathbf{B_{4}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ | (2b) | O I |
| $\mathbf{B_{5}}$ | = | $\frac{1}{2} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ | (2c) | Na I |
| $\mathbf{B_{6}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ | (2c) | Na I |
| $\mathbf{B_{7}}$ | = | $x_{4} \, \mathbf{a}_{1}+\left(x_{4} + \frac{1}{2}\right) \, \mathbf{a}_{2}$ | = | $a x_{4} \,\mathbf{\hat{x}}+a \left(x_{4} + \frac{1}{2}\right) \,\mathbf{\hat{y}}$ | (4g) | O II |
| $\mathbf{B_{8}}$ | = | $- x_{4} \, \mathbf{a}_{1}- \left(x_{4} - \frac{1}{2}\right) \, \mathbf{a}_{2}$ | = | $- a x_{4} \,\mathbf{\hat{x}}- a \left(x_{4} - \frac{1}{2}\right) \,\mathbf{\hat{y}}$ | (4g) | O II |
| $\mathbf{B_{9}}$ | = | $- \left(x_{4} - \frac{1}{2}\right) \, \mathbf{a}_{1}+x_{4} \, \mathbf{a}_{2}$ | = | $- a \left(x_{4} - \frac{1}{2}\right) \,\mathbf{\hat{x}}+a x_{4} \,\mathbf{\hat{y}}$ | (4g) | O II |
| $\mathbf{B_{10}}$ | = | $\left(x_{4} + \frac{1}{2}\right) \, \mathbf{a}_{1}- x_{4} \, \mathbf{a}_{2}$ | = | $a \left(x_{4} + \frac{1}{2}\right) \,\mathbf{\hat{x}}- a x_{4} \,\mathbf{\hat{y}}$ | (4g) | O II |
References
- R. H. Mitchell, P. C. Burns, K. S. Knight, C. J. Howard, and A. R. Chakhmouradian, Observations on the crystal structures of lueshite, Phys. Chem. Minerals 41, 393–401 (2014), doi:10.1007/s00269-014-0657-1.
- P. Vousden, The Structure of Ferroelectric Sodium Niobate at Room Temperature, Acta Cryst. 4, 545–551 (1951), doi:10.1107/S0365110X51001768.
First cited in
- N. Anderson, M. J. Mehl, H. Eckert, S. Divilov, X. Campilongo, S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 5. Submitted to Computational Materials Science (2026).
Geometry files
Prototype Generator
aflow --proto=ABC3_tP10_127_c_a_bg --params=$a,c/a,x_{4}$