p21/m11 2/m Monoclinic/Rectangular No. 15 p21/m11 Patterson symmetry p2/m11

Origin at -1 on 21

 Asymmetric unit 0 ≤ x ≤ 1/4; 0 ≤ y ≤ 1

Symmetry operations

 (1)  1       (1 | 0, 0, 0) (2)  2 (1/2, 0, 0)   x, 0, 0       (2x | 1/2, 0, 0) (3)  -1   0, 0, 0       (-1 | 0, 0, 0) (4)  m   1/4, y, z       (mx | 1/2, 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 d 1
 (1) x, y, z (2) x + 1/2, -y, -z (3) -x, -y, -z (4) -x + 1/2, y, z
h0: h = 2n
Special: as above, plus
 2 c m
 1/4, y, z 3/4, -y, -z
no extra conditions
 2 b -1
 0, 1/2, 0 1/2, 1/2, 0
hk: h = 2n
 2 a -1
 0, 0, 0 1/2, 0, 0
hk: h = 2n

Symmetry of special projections

 Along [001]   p2mg a' = a   b' = bp    Origin at 0, 0, z Along [100]   211 a' = b    Origin at x, 0, 0 Along [010]   2mg a' = a    Origin at 0, y, 0

Maximal non-isotypic subgroups

 I [2] pm11 (11) 1; 4 [2] p2111 (9) 1; 2 [2] p-1 (2) 1; 3
 IIa none
 IIb [2] p21/b11 (b' = 2b) (17)

Maximal isotypic subgroups of lowest index

 IIc [2] p21/m11 (b' = 2b) (15); [3] p21/m11 (a' = 3a) (15)

Minimal non-isotypic supergroups

 I [2] pmam (40); [2] pmma (41); [2] pbma (45); [2] pmmn (46)
 II [2] c2/m11 (18); [2] p2/m11 (a' = 1/2a) (14)