Electron microscopy
 
P212121 (19) Space Group
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Table 1665. P212121 (19) space group.

Name in the International Tables for Crystallography
P212121 P
47 222
Crystal system
Orthorhombic mmm
Asymm
0 ≤ x ≤ 1/2 and 0 ≤ y ≤ 1/2 and 0 ≤ z ≤ 1
4 Absence of reflections

h00 for h = 2n+1 (odd) (21-screw axis along a), 0k0 for k = 2n+1 (odd) (21-screw axis along b)

Translation
 
Symmetry (atomic coordinates)
X, Y, Z; 1/2-X, -Y, 1/2+Z; -X, 1/2+Y, 1/2-Z; 1/2+X, 1/2-Y, -Z
Crystal symmetry
Is non-centrosymmetric because it has not -x,-y,-z in its symmetry.
Reflection & intensity
1 0 0 0.8   2 0 0 5135.4   4 1 0 2654.1
0 1 0 0.6 2 1 0 295.2 5 0 0 0.2
0 2 0 7899.4 2 2 0 2654.1 5 1 0 895.6
0 3 0 0.3 2 3 0 397.8 6 0 0 2654.1
0 4 0 4372.5 2 3 0 397.8 6 1 0 1243.8
1 1 0 3742.3 2 4 0 1243.8 7 0 0 0.1
1 2 0 1200.1 3 0 0 0.3 7 1 0 367.1
1 3 0 5135.4 3 4 0 895.1 8 0 0 1243.8
1 4 0 336.4 4 0 0 3742.3 8 1 0 2654.1
Remarks
A non-chiral Sohncke space group with chiral structures: The sets of coordinates include enantiometric pairs.
Crystal examples
 

 

 

 

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