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Crystal Lab › Prototype structures › Orthorhombic

Ca-Malate-dihydrate (CaC₄H₄O₅cdot2H₂O)

Orthorhombic · space group P212121 (No. 19) · Pearson oP80

Symmetry elements and Wyckoff positions (interactive)

Ca-Malate-dihydrate (CaC₄H₄O₅cdot2H₂O) in P212121

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

Unit cell

Lattice constants
a = 6.728 Å, b = 8.448 Å, c = 13.413 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
762.4 ų
Atoms in the conventional cell
80 (C 16, Ca 4, H 32, O 28)
Formula units Z
4
Pearson symbol
oP80 — orthorhombic, primitive lattice, 80 atoms per conventional cell
Symmetry operations
4 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
C1C4a40.19490.18420.3001
C2C4a40.03270.32010.8686
C3C4a40.30140.04100.2554
C4C4a40.01030.42380.7775
Ca5Ca4a40.04240.18870.0727
H10H4a40.40010.10790.7018
H11H4a40.19380.04430.8182
H12H4a40.09640.37550.7152
H13H4a40.40730.46330.2886
H6H4a40.29370.49190.5520
H7H4a40.44540.48480.6470
H8H4a40.11810.35690.4609
H9H4a40.43780.12410.4565
O14O4a40.30930.02430.6739
O15O4a40.24750.22660.3857
O16O4a40.07340.47630.0772
O17O4a40.38460.23430.0882
O18O4a40.04390.43160.5041
O19O4a40.05990.24740.2510
O20O4a40.20390.28890.8991

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 80 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

A4BC8D7_oP80_19_4a_a_8a_7a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP80, then the space-group number 19, then the Wyckoff letters occupied by each element in turn (C: 4a; C: 4a; C: 4a; C: 4a; Ca: 4a; H: 4a; H: 4a; H: 4a; H: 4a; H: 4a; H: 4a; H: 4a; H: 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: Ca-Malate-dihydrate.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A4BC8D7_oP80_19_4a_a_8a_7a-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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