cm m Rectangularinfo
No. 5 c1m1 Patterson symmetry c2mm

symmetry group diagram

Origin on m

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

Symmetry operations

For (0, 0)+ set

(1)  1   (2)  m   0, y

For (1/2, 1/2)+ set

(1)  t(1/2, 1/2)   (2)  b   1/4, y

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

Positions

Multiplicity, Wyckoff letter,
Site symmetry		 Coordinates Reflection conditions
 (0,  0)+  (1/2,  1/2)+  General:
4 b 1
(1) x, y(2) -x, y 
hk : h + k = 2n
h0 : h = 2n
0k : k = 2n
    Special: as above, plus
2 a  . m . 
0, y
no extra conditions

Maximal non-isomorphic subgroups

I[2] c1 (p1, 1)1+
IIa[2] pg (4)1; 2 + (1/2, 1/2)
 [2] pm (3)1; 2
IIbnone

Maximal isomorphic subgroups of lowest index

IIc[3] cm (a' = 3a) (5); [3] cm (b' = 3b) (5)

Minimal non-isomorphic supergroups

I[2] c2mm (9); [3] p3m1 (14); [3] p31m (15)
II[2] pm(a' = 1/2 a, b' = 1/2 b) (3)








































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