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

symmetry group diagram

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   1/4yz
      (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) xyz (2) x + 1/2-y-z (3) -x-y-z (4) -x + 1/2yz
h0: h = 2n
    Special: as above, plus
2 c  m 
1/4yz 3/4-y-z
no extra conditions
2 b  -1 
0, 1/2, 0 1/21/2, 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]   [script p]211
a' = b   
Origin at x, 0, 0
Along [010]   [script p]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)








































to end of page
to top of page