pm21b m2m Orthorhombic/Rectangular No. 28 pm21b Patterson symmetry pmmm

Origin on m21b

 Asymmetric unit 0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1; 0 ≤ z

Symmetry operations

 (1)  1       (1 | 0, 0, 0) (2)  2 (0, 1/2, 0)   0, y, 0       (2y | 0, 1/2, 0) (3)  b   x, y, 0       (mz | 0, 1/2, 0) (4)  m   0, y, z       (mx | 0, 0, 0)

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

Positions

Multiplicity, Wyckoff letter,
Site symmetry
Coordinates Reflection conditions

General:
 4 c 1
 (1) x, y, z (2) -x, y + 1/2, -z (3) x, y + 1/2, -z (4) -x, y, z
hk: k = 2n
0k: k = 2n
Special: no extra conditions
 2 b m . .
 1/2, y, z 1/2, y + 1/2, -z
 2 a m . .
 0, y, z 0, y + 1/2, -z

Symmetry of special projections

 Along [001]   p1m1 a' = a   b' = 1/2b    Origin at 0, 0, z Along [100]   11g a' = b    Origin at x, 0, 0 Along [010]   2mm a' = a    Origin at 0, y, 0

Maximal non-isotypic subgroups

 I [2] pm11 (11) 1; 4 [2] p1211 (p2111, 9) 1; 2 [2] p11b (p11a, 5) 1; 3
 IIa none
 IIb [2] pm21n (a' = 2a) (32)

Maximal isotypic subgroups of lowest index

 IIc [2] pm21b (a' = 2a) (28); [3] pm21b (b' = 3b) (28)

Minimal non-isotypic supergroups

 I [2] pmma (41); [2] pbma (45)
 II [2] cm2m (35); [2] cm2e (36); [2] pm2m (b' = 1/2b) (27)