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Crystal Lab › Prototype structures › Orthorhombic

CaB₂O₄ (III)

Orthorhombic · space group Pna21 (No. 33) · Pearson oP84

Symmetry elements and Wyckoff positions (interactive)

CaB₂O₄ (III) in Pna21

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

Unit cell

Lattice constants
a = 11.380 Å, b = 6.307 Å, c = 11.304 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
811.3 ų
Atoms in the conventional cell
84 (B 24, Ca 12, O 48)
Formula units Z
12
Pearson symbol
oP84 — orthorhombic, primitive lattice, 84 atoms per conventional cell
Symmetry operations
4 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
B1B4a40.14010.25290.5390
B2B4a40.25100.41930.0515
B3B4a40.21310.11910.7403
B4B4a40.32220.10060.9442
B5B4a40.46580.01830.4800
B6B4a40.47480.37580.2477
Ca7Ca4a40.07350.05040.0000
Ca8Ca4a40.03260.66000.2339
Ca9Ca4a40.25310.11290.2796
O10O4a40.26570.19440.0459
O11O4a40.21710.47040.1734
O12O4a40.07170.02970.2009
O13O4a40.45470.17150.2567
O14O4a40.20090.37500.4486
O15O4a40.14560.03220.5116
O16O4a40.00610.30090.5305
O17O4a40.17340.29460.6635
O18O4a40.10690.02200.7981
O19O4a40.28700.20460.8336
O20O4a40.45630.13700.9458
O21O4a40.15040.47680.9668

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 84 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

A2BC4_oP84_33_6a_3a_12a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP84, then the space-group number 33, then the Wyckoff letters occupied by each element in turn (B: 4a; B: 4a; B: 4a; B: 4a; B: 4a; B: 4a; Ca: 4a; Ca: 4a; Ca: 4a; O: 4a; O: 4a; O: 4a; O: 4a; O: 4a; O: 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.

Note: CaB₂O₄ III.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2BC4_oP84_33_6a_3a_12a-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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