2mm 2mm Orthorhombic No. 18 2mm Patterson symmetry mmm

Origin on 2mm

 Asymmetric unit 0 ≤ y; 0 ≤ z ≤ 1/2

Symmetry operations

 (1)  1      (1 | 0, 0, 0) (2)  2   x, 0, 0      (2x | 0, 0, 0) (3)  m   x, y, 0      (mz | 0, 0, 0) (4)  m   x, 0, z      (my | 0, 0, 0)

Generators selected (1); t(0, 0, 1); (2); (3)

Positions

Multiplicity, Wyckoff letter,
Site symmetry
Coordinates Reflection conditions

General:
 4 f 1
 (1) x, y, z (2) x, -y, -z (3) x, y, -z (4) x, -y, z
no conditions
Special: no extra conditions
 2 e . m .
 x, 0, z x, 0, -z
 2 d . . m
 x, y, 1/2 x, -y, 1/2
 2 c . . m
 x, y, 0 x, -y, 0
 1 b 2 m m
 x, 0, 1/2
 1 a 2 m m
 x, 0, 0

Symmetry of special projections

 Along [001]   11mOrigin at 0, 0, z Along [100]   2mma' = c   Origin at x, 0, 0 Along [010]   1m1a' = c   Origin at 0, y, 0

Maximal non-isotypic non-enantiomorphic subgroups

 I [2] 11m (10) 1; 3 [2] 1m1 (m11, 4) 1; 4 [2] 211 (3) 1; 2
 IIa none
 IIb [2] 2cm (c' = 2c) (19)

Maximal isotypic subgroups and enantiomorphic subgroups of lowest index

 IIc [2] 2mm (c' = 2c) (18)

Minimal non-isotypic non-enantiomorphic supergroups

 I [2] mmm (20); [2] mcm (22); [3] -6m2 (71)
 II none