[script p]mc21 mm2 Orthorhombic
No. 17 [script p]mc21 Patterson symmetry [script p]mmm

symmetry group diagram

Origin on mc21

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

Symmetry operations

(1)  1   (2)  2(1/2)   0, 0, z(3)  c   x, 0, z(4)  m   0, y, z

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

Positions

Multiplicity, Wyckoff letter,
Site symmetry		 Coordinates Reflection conditions
 General:
4 b 1
(1) x, y, z(2) -x, -y, z + 1/2(3) x, -y, z + 1/2(4) -x, y, z
l: l = 2n
  Special: no extra conditions
2 a  m . . 
0, y, z0, -y, z + 1/2

Symmetry of special projections

Along [001]   2mm

Origin at 0, 0, z 		Along [100]   [script p]11g
a' = c   
Origin at x, 0, 0 		Along [010]   [script p]11m
a' = 1/2c   
Origin at 0, y, 0

Maximal non-isotypic non-enantiomorphic subgroups

I[2] [script p]1121 (9)1; 2
 [2] [script p]1c1 ([script p]c11, 5)1; 3
 [2] [script p]m11 (4)1; 4
IIa none
IIbnone

Maximal isotypic subgroups and enantiomorphic subgroups of lowest index

IIc[3] [script p]mc21 (c' = 3c) (17)

Minimal non-isotypic non-enantiomorphic supergroups

I[2] [script p]mcm (22); [3] [script p]63mc (70)
II[2] [script p]mm2 (c' = 1/2c) (15)








































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