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Crystal Lab › Prototype structures › Orthorhombic

Koechlinite (Room temperature Bi₂MoO₆)

Orthorhombic · space group Pca21 (No. 29) · Pearson oP36 · mineral: koechlinite

Symmetry elements and Wyckoff positions (interactive)

Koechlinite (Room temperature Bi₂MoO₆) in Pca21

Setting
Loading the group…
x = 0.10, y = 0.17, z = 0.08

Unit cell

Lattice constants
a = 5.482 Å, b = 16.199 Å, c = 5.509 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
489.2 ų
Atoms in the conventional cell
36 (Bi 8, Mo 4, O 24)
Formula units Z
4
Pearson symbol
oP36 — orthorhombic, primitive lattice, 36 atoms per conventional cell
Symmetry operations
4 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Bi1Bi4a40.51800.42320.9814
Bi2Bi4a40.48220.07830.9897
Mo3Mo4a40.00280.24880.0000
O4O4a40.05560.14070.0959
O5O4a40.25940.99830.2776
O6O4a40.23600.50060.2664
O7O4a40.69170.23220.2524
O8O4a40.21210.26340.3550
O9O4a40.56540.35890.5700

The multiplicity and the Wyckoff letter say how many copies of the site the group makes in one cell and on which kind of symmetry element the site sits; the 36 atoms drawn above are these sites multiplied by all 4 operations. Press Wyckoff under Colour to see the sites, and tick a symmetry element on the left to see which atoms lie on it.

How to read the label

A2BC6_oP36_29_2a_a_6a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP36, then the space-group number 29, then the Wyckoff letters occupied by each element in turn (Bi: 4a; Bi: 4a; Mo: 4a; O: 4a; O: 4a; O: 4a; O: 4a; O: 4a; O: 4a). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Bi₂WO₆ (russelite) <!--beginning with an

Note: Koechlinite (RT).

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2BC6_oP36_29_2a_a_6a-001 (M. J. Mehl et al., Comput. Mater. Sci. 136, S1 (2017); D. Hicks et al., ibid. 161, S1 (2019) and 199, 110450 (2021); S. Eckert et al., ibid. 240, 112988 (2024)). Symmetry elements, Wyckoff assignment and the diagram are computed on this page from the group operations.

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