Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: ABC2_oP8_31_a_a_2a-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.

Links to this page

https://aflow.org/p/TZ68
or https://aflow.org/p/ABC2_oP8_31_a_a_2a-001
or PDF Version

Guyanaite (β-CrOOH) Structure: ABC2_oP8_31_a_a_2a-001

Picture of Structure; Click for Big Picture
Prototype CrHO$_{2}$
AFLOW prototype label ABC2_oP8_31_a_a_2a-001
Mineral name guyanaite
ICSD none
Pearson symbol oP8
Space group number 31
Space group symbol $Pmn2_1$
AFLOW prototype command aflow --proto=ABC2_oP8_31_a_a_2a-001
--params=$a, \allowbreak b/a, \allowbreak c/a, \allowbreak y_{1}, \allowbreak z_{1}, \allowbreak y_{2}, \allowbreak z_{2}, \allowbreak y_{3}, \allowbreak z_{3}, \allowbreak y_{4}, \allowbreak z_{4}$

Other compounds with this structure

InOOH


  • CrOOH is found naturally in three forms. They are usually found together with Cr$_{2}$O$_{3}$ in a mineral known as merumite (Milton, 1976):
  • (Jahn, 2012) give the data for this structure in the $P2_{1}nm$ setting of space group #31. We use FINDSYM to transform this to the standard $Pmn2_{1}$ setting.
  • Space group $Pmn2_{1}$ #31 does not specify the origin of the $z$-axis. We choose it by setting $z_{1} = 0$ for the position of the chromium atom.

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

Basis vectors

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

References

  • S. Jahn, B. Wunder, M. Koch-Müller, L. Tarrieu, M. Pöhle, A. Watenphul, and M. N. Taran, Pressure-induced hydrogen bond symmetrisation in guyanaite, β-CrOOH: evidence from spectroscopy and {\em ab initio} simulations, Eur. J. Mineral. 24, 839–850 (2012), doi:10.1127/0935-1221/2012/0024-2228.
  • C. Milton, D. E. Appleman, M. H. Appleman, E. C. T. Chao, F. Cuttitta, J. I. Dinnin, E. J. Dwornik, B. L. Ingram, and J. H. J. Rose, Merumite – A Complex Assemblage of Chromium Minerals from Guyanna (1976). Geological Survey Professional Paper 887.

Prototype Generator

aflow --proto=ABC2_oP8_31_a_a_2a --params=$a,b/a,c/a,y_{1},z_{1},y_{2},z_{2},y_{3},z_{3},y_{4},z_{4}$

Species:

Running:

Output: