p21/b11 2/m Monoclinic/Rectangular
No. 17 p21/b11 Patterson symmetry p2/m11

symmetry group diagram

Origin at -1

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

Symmetry operations

(1)  1
      (1 | 0, 0, 0)
(2)  2 (1/2, 0, 0)   x1/4, 0
      (2x | 1/21/2, 0)
(3)  -1   0, 0, 0
      (-1 | 0, 0, 0)
(4)  b   1/4yz
      (mx | 1/21/2, 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) xyz (2) x + 1/2-y + 1/2-z (3) -x-y-z (4) -x + 1/2y + 1/2z
h0: h = 2n
0k: k = 2n
    Special: as above, plus
2 b  -1 
0, 1/2, 0 1/2, 0, 0
hk: h + k = 2n
2 a  -1 
0, 0, 0 1/21/2, 0
hk: h + k = 2n

Symmetry of special projections

Along [001]   p2gg
a' = a   b' = bp   
Origin at 0, 0, z
Along [100]   [script p]211
a' = 1/2b   
Origin at x, 0, 0
Along [010]   [script p]2mg
a' = a   
Origin at 0, y, 0

Maximal non-isotypic subgroups


I [2] pb11 (12) 1; 4
  [2] p2111 (9) 1; 2
  [2] p-1 (2) 1; 3
IIa none
IIb none

Maximal isotypic subgroups of lowest index


IIc [3] p21/b11 (a' = 3a) (17)

Minimal non-isotypic supergroups


I [2] pman (42); [2] pbaa (43); [2] pbam (44); [2] pbma (45)
II [2] c2/m11 (18); [2] p21/m11 (b' = 1/2b) (15); [2] p2/b11 (a' = 1/2a) (16)








































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