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Crystal Lab › Prototype structures › Orthorhombic

La₃NbO₇

Orthorhombic · space group Cmcm (No. 63) · Pearson oC44

Symmetry elements and Wyckoff positions (interactive)

La₃NbO₇ in Cmcm

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

Unit cell

Lattice constants
a = 11.167 Å, b = 7.629 Å, c = 7.753 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
660.5 ų
Atoms in the conventional cell
44 (La 12, Nb 4, O 28)
Formula units Z
4
Pearson symbol
oC44 — orthorhombic, base-centred lattice, 44 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
La1La4a40.00000.00000.0000
Nb3Nb4b40.00000.50000.0000
O4O4c40.00000.44900.2500
La2La8g80.22530.30250.2500
O5O8g80.63900.52800.2500
O6O16h160.12900.32000.0360

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 44 atoms drawn above are these sites multiplied by all 16 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

A3BC7_oC44_63_ag_b_cgh-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oC44, then the space-group number 63, then the Wyckoff letters occupied by each element in turn (La: 4a; Nb: 4b; O: 4c; La: 8g; O: 8g; O: 16h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Eu₃IrO₇, Nd₃NbO₇, Pr₃IrO₇ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A3BC7_oC44_63_ag_b_cgh-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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