Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: AB3C2_tP12_136_a_bd_f-001

If you are using this page, please cite:
H. Eckert, S. Divilov, M. J. Mehl, D. Hicks, A. C. Zettel, M. Esters. X. Campilongo and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 4. Submitted to Computational Materials Science.

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https://aflow.org/p/2PDY
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α-Li$_{3}$BN$_{2}$ Structure: AB3C2_tP12_136_a_bd_f-001

Picture of Structure; Click for Big Picture
Prototype BLi$_{3}$N$_{2}$
AFLOW prototype label AB3C2_tP12_136_a_bd_f-001
ICSD 655673
Pearson symbol tP12
Space group number 136
Space group symbol $P4_2/mnm$
AFLOW prototype command aflow --proto=AB3C2_tP12_136_a_bd_f-001
--params=$a, \allowbreak c/a, \allowbreak x_{4}$

  • (Yamane, 1987) find a phase transition from $\alpha$- to $\beta$–Li$_{3}$BN$_{2}$ at 1135K. The $\beta$–Li$_{3}$BN$_{2}$ phase has space group $P2_{1}/c$ #14 and four formula units in a monoclinic cell, compared to two units in the $\alpha$- phase, but they did not describe the atomic positions for $\beta$–Li$_{3}$BN$_{2}$.
  • (Yamane, 1987) put this in space group $P4_{2}2_{1}2$ #94, but the positions of the lithium atoms are such that there is an inversion cite, placing the system in space group $P4_{2}/mnm$ #136. (Cenzual, 1991)

\[ \begin{array}{ccc} \mathbf{a_{1}}&=&a \,\mathbf{\hat{x}}\\\mathbf{a_{2}}&=&a \,\mathbf{\hat{y}}\\\mathbf{a_{3}}&=&c \,\mathbf{\hat{z}} \end{array}\]

Basis vectors

Lattice coordinates Cartesian coordinates Wyckoff position Atom type
$\mathbf{B_{1}}$ = $0$ = $0$ (2a) B I
$\mathbf{B_{2}}$ = $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (2a) B I
$\mathbf{B_{3}}$ = $\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}c \,\mathbf{\hat{z}}$ (2b) Li I
$\mathbf{B_{4}}$ = $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}$ (2b) Li I
$\mathbf{B_{5}}$ = $\frac{1}{2} \, \mathbf{a}_{2}+\frac{1}{4} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{4}c \,\mathbf{\hat{z}}$ (4d) Li II
$\mathbf{B_{6}}$ = $\frac{1}{2} \, \mathbf{a}_{2}+\frac{3}{4} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{3}{4}c \,\mathbf{\hat{z}}$ (4d) Li II
$\mathbf{B_{7}}$ = $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{4} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{4}c \,\mathbf{\hat{z}}$ (4d) Li II
$\mathbf{B_{8}}$ = $\frac{1}{2} \, \mathbf{a}_{1}+\frac{3}{4} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{3}{4}c \,\mathbf{\hat{z}}$ (4d) Li II
$\mathbf{B_{9}}$ = $x_{4} \, \mathbf{a}_{1}+x_{4} \, \mathbf{a}_{2}$ = $a x_{4} \,\mathbf{\hat{x}}+a x_{4} \,\mathbf{\hat{y}}$ (4f) N I
$\mathbf{B_{10}}$ = $- x_{4} \, \mathbf{a}_{1}- x_{4} \, \mathbf{a}_{2}$ = $- a x_{4} \,\mathbf{\hat{x}}- a x_{4} \,\mathbf{\hat{y}}$ (4f) N I
$\mathbf{B_{11}}$ = $- \left(x_{4} - \frac{1}{2}\right) \, \mathbf{a}_{1}+\left(x_{4} + \frac{1}{2}\right) \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $- a \left(x_{4} - \frac{1}{2}\right) \,\mathbf{\hat{x}}+a \left(x_{4} + \frac{1}{2}\right) \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (4f) N I
$\mathbf{B_{12}}$ = $\left(x_{4} + \frac{1}{2}\right) \, \mathbf{a}_{1}- \left(x_{4} - \frac{1}{2}\right) \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $a \left(x_{4} + \frac{1}{2}\right) \,\mathbf{\hat{x}}- a \left(x_{4} - \frac{1}{2}\right) \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (4f) N I

References

  • H. Yamane, S. Kikkawa, and M. Koizumi, High- and low-temperature phases of lithium boron nitride, Li$_{3}$BN$_{2}$: Preparation, phase relation, crystal structure, and ionic conductivity, J. Solid State Chem. 71, 1–11 (1987), doi:10.1016/0022-4596(87)90135-6.

Found in

  • K. Cenzual, L. M. Gelato, M. Penzo, and E. Parthé, Inorganic structure types with revised space groups. I, Acta Crystallogr. Sect. B 47, 433–439 (1991), doi:10.1107/S0108768191000903.

Prototype Generator

aflow --proto=AB3C2_tP12_136_a_bd_f --params=$a,c/a,x_{4}$

Species:

Running:

Output: