Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: AB_hP8_194_ac_f-003

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/JV7G
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LiO Structure: AB_hP8_194_ac_f-003

Picture of Structure; Click for Big Picture
Prototype LiO
AFLOW prototype label AB_hP8_194_ac_f-003
ICSD 25530
Pearson symbol hP8
Space group number 194
Space group symbol $P6_3/mmc$
AFLOW prototype command aflow --proto=AB_hP8_194_ac_f-003
--params=$a, \allowbreak c/a, \allowbreak z_{3}$

Other compounds with this structure

$\beta$-KTe,  $\beta$-NaS,  $\beta$-NaTe


  • (Fehér, 1953) and (Föppl, 1957) presented competing structures for LiO, both in space group $P\overline{6}$ #174. First-principles calculation by (Cota, 2005) and (Chen, 2011) suggest that the Föppl structure is correct, but show that the proper space group is $P6_{3}/mmc$ #194. This is generally held to be the correct structure, e.g. (Jain, 2013). We use the symmetrization of Föppl's original data made by (Cota, 2005).
  • The ICSD entry is from Föppl, 1957), updated to make the space group $P6_{3}/mmc$.

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

Basis vectors

Lattice coordinates Cartesian coordinates Wyckoff position Atom type
$\mathbf{B_{1}}$ = $0$ = $0$ (2a) Li I
$\mathbf{B_{2}}$ = $\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}c \,\mathbf{\hat{z}}$ (2a) Li I
$\mathbf{B_{3}}$ = $\frac{1}{3} \, \mathbf{a}_{1}+\frac{2}{3} \, \mathbf{a}_{2}+\frac{1}{4} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{4}c \,\mathbf{\hat{z}}$ (2c) Li II
$\mathbf{B_{4}}$ = $\frac{2}{3} \, \mathbf{a}_{1}+\frac{1}{3} \, \mathbf{a}_{2}+\frac{3}{4} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{3}{4}c \,\mathbf{\hat{z}}$ (2c) Li II
$\mathbf{B_{5}}$ = $\frac{1}{3} \, \mathbf{a}_{1}+\frac{2}{3} \, \mathbf{a}_{2}+z_{3} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+c z_{3} \,\mathbf{\hat{z}}$ (4f) O I
$\mathbf{B_{6}}$ = $\frac{2}{3} \, \mathbf{a}_{1}+\frac{1}{3} \, \mathbf{a}_{2}+\left(z_{3} + \frac{1}{2}\right) \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+c \left(z_{3} + \frac{1}{2}\right) \,\mathbf{\hat{z}}$ (4f) O I
$\mathbf{B_{7}}$ = $\frac{2}{3} \, \mathbf{a}_{1}+\frac{1}{3} \, \mathbf{a}_{2}- z_{3} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}- c z_{3} \,\mathbf{\hat{z}}$ (4f) O I
$\mathbf{B_{8}}$ = $\frac{1}{3} \, \mathbf{a}_{1}+\frac{2}{3} \, \mathbf{a}_{2}- \left(z_{3} - \frac{1}{2}\right) \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}- c \left(z_{3} - \frac{1}{2}\right) \,\mathbf{\hat{z}}$ (4f) O I

References

  • L. G. Cota and P. de la Mora, On the structure of lithium peroxide, Li$_{2}$O$_{2}$, Acta Crystallogr. Sect. B 61, 133–136 (2005), doi:10.1107/S0108768105003629.
  • F. Fehér, I. von Wilucki, and G. Dost, Beiträge zur Kenntnis des Wasserstoffperoxyds und seiner Derivate, VII. Mitteil.: Über die Kristallstruktur des Lithiumperoxyds, Li$_{2}$O$_{2}$, Chem. Ber. 86, 1429–1437 (1953), doi:10.1002/cber.19530861111.
  • H. Föppl, Die Kristallstrukturen der Alkaliperoxyde, Z. Anorganische und Allgemeine Chemie 291, 12–50 (1957), doi:10.1002/zaac.19572910104.
  • A. Jain, S. Ping, G. Hautier, W. Chen, W. D. Richards, S. Dacek, S. Cholia, D. Gunter, D. Skinner, G. Ceder, and K. A. Persson, Commentary: The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1, 011002 (2013), doi:10.1063/1.4812323.

Found in

  • M. K. Y. Chan, E. L. Shirley, N. K. Karan, M. Balasubramanian, Y. Ren, J. P. Greeley, and T. T. Fister, Structure of Lithium Peroxide, J. Phys. Chem. Lett. 2, 2483–2486 (2011), doi:10.1021/jz201072b.

Prototype Generator

aflow --proto=AB_hP8_194_ac_f --params=$a,c/a,z_{3}$

Species:

Running:

Output: