VN (Low-temperature) Structure: AB_tP8_111_n_n-001
| Prototype | NV |
| AFLOW prototype label | AB_tP8_111_n_n-001 |
| ICSD | none |
| Pearson symbol | tP8 |
| Space group number | 111 |
| Space group symbol | $P\overline{4}2m$ |
| AFLOW prototype command |
aflow --proto=AB_tP8_111_n_n-001
--params=$a, \allowbreak c/a, \allowbreak x_{1}, \allowbreak z_{1}, \allowbreak x_{2}, \allowbreak z_{2}$ |
- Above 205K vanadium nitride transforms into the rock salt ($B1$) structure.
- We use the data taken at 150K.
- (Kubel, 1988) place this structure in space group $P\overline{4}2m$ #111, but since $c/a ≈ 1$ the default tolerance of AFLOW places this in the cubic space group $P\overline{4}3m$ #215. It is likely that first-principles calculations will place this compound in the higher symmetry space group.
- The $P\overline{4}2m$ structure may be recovered from AFLOW using the commmand
- aflow --proto=AB_tP8_111_n_n:N:V --params=a,c/a,x$_{1}$,z$_{1}$,x$_{2}$,z$_{2}$ --tolerance=0.001 .
- We could not find an ICSD entry for (Kubel, 1988).
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&a \,\mathbf{\hat{x}}\\\mathbf{a_{2}}&=&a \,\mathbf{\hat{y}}\\\mathbf{a_{3}}&=&c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $x_{1} \, \mathbf{a}_{1}+x_{1} \, \mathbf{a}_{2}+z_{1} \, \mathbf{a}_{3}$ | = | $a x_{1} \,\mathbf{\hat{x}}+a x_{1} \,\mathbf{\hat{y}}+c z_{1} \,\mathbf{\hat{z}}$ | (4n) | N I |
| $\mathbf{B_{2}}$ | = | $- x_{1} \, \mathbf{a}_{1}- x_{1} \, \mathbf{a}_{2}+z_{1} \, \mathbf{a}_{3}$ | = | $- a x_{1} \,\mathbf{\hat{x}}- a x_{1} \,\mathbf{\hat{y}}+c z_{1} \,\mathbf{\hat{z}}$ | (4n) | N I |
| $\mathbf{B_{3}}$ | = | $x_{1} \, \mathbf{a}_{1}- x_{1} \, \mathbf{a}_{2}- z_{1} \, \mathbf{a}_{3}$ | = | $a x_{1} \,\mathbf{\hat{x}}- a x_{1} \,\mathbf{\hat{y}}- c z_{1} \,\mathbf{\hat{z}}$ | (4n) | N I |
| $\mathbf{B_{4}}$ | = | $- x_{1} \, \mathbf{a}_{1}+x_{1} \, \mathbf{a}_{2}- z_{1} \, \mathbf{a}_{3}$ | = | $- a x_{1} \,\mathbf{\hat{x}}+a x_{1} \,\mathbf{\hat{y}}- c z_{1} \,\mathbf{\hat{z}}$ | (4n) | N I |
| $\mathbf{B_{5}}$ | = | $x_{2} \, \mathbf{a}_{1}+x_{2} \, \mathbf{a}_{2}+z_{2} \, \mathbf{a}_{3}$ | = | $a x_{2} \,\mathbf{\hat{x}}+a x_{2} \,\mathbf{\hat{y}}+c z_{2} \,\mathbf{\hat{z}}$ | (4n) | V I |
| $\mathbf{B_{6}}$ | = | $- x_{2} \, \mathbf{a}_{1}- x_{2} \, \mathbf{a}_{2}+z_{2} \, \mathbf{a}_{3}$ | = | $- a x_{2} \,\mathbf{\hat{x}}- a x_{2} \,\mathbf{\hat{y}}+c z_{2} \,\mathbf{\hat{z}}$ | (4n) | V I |
| $\mathbf{B_{7}}$ | = | $x_{2} \, \mathbf{a}_{1}- x_{2} \, \mathbf{a}_{2}- z_{2} \, \mathbf{a}_{3}$ | = | $a x_{2} \,\mathbf{\hat{x}}- a x_{2} \,\mathbf{\hat{y}}- c z_{2} \,\mathbf{\hat{z}}$ | (4n) | V I |
| $\mathbf{B_{8}}$ | = | $- x_{2} \, \mathbf{a}_{1}+x_{2} \, \mathbf{a}_{2}- z_{2} \, \mathbf{a}_{3}$ | = | $- a x_{2} \,\mathbf{\hat{x}}+a x_{2} \,\mathbf{\hat{y}}- c z_{2} \,\mathbf{\hat{z}}$ | (4n) | V I |
References
- F. Kubel, W. Lengauer, K. Yvon, K. Knorr, and A. Junod, Structural phase transition at 205 K in stoichiometric vanadium nitride, Phys. Rev. B 38, 12908–12912 (1988), doi:10.1103/PhysRevB.38.12908.
- H. T. Stokes and D. M. Hatch, {\em FINDSYM}: program for identifying the space-group symmetry of a crystal, J. App. Crystallogr. 38, 237–238 (2005), doi:10.1107/S0021889804031528.
- D. Hicks, C. Oses, E. Gossett, G. Gomez, R. H. Taylor, C. Toher, M. J. Mehl, O. Levy, and S. Curtarolo, AFLOW-SYM: platform for the complete, automatic and self-consistent symmetry analysis of crystals, Acta Crystallogr. Sect. A 74, 184–203 (2018), doi:10.1107/S2053273318003066.
- A. L. Speck, Single-crystal structure validation with the program PLATON, J. App. Crystallogr. 36, 7–13 (2003), doi:10.1107/S0021889802022112.
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_tP8_111_n_n --params=$a,c/a,x_{1},z_{1},x_{2},z_{2}$