P2 C21 2 Monoclinic info
No. 3 P121 Patterson symmetry P12/m1
UNIQUE AXIS b

symmetry group diagram

Origin on 2

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

Symmetry operations

(1)  1   (2)  2   0, y, 0  

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

Positions

Multiplicity, Wyckoff letter,
Site symmetry		 Coordinates Reflection conditions
 General:
2 e 1
(1) x, y, z(2) -x, y, -z
no conditions
    Special: as above, plus
1 d  2 
1/2, y, 1/2
no extra conditions
1 c  2 
1/2, y, 0
no extra conditions
1 b  2 
0, y, 1/2
no extra conditions
1 a  2 
0, y, 0
no extra conditions

Symmetry of special projections

Along [001]   p1m1
a' = ap   b' = b   
Origin at 0, 0, z		Along [100]   p11m
a' = b   b' = cp   
Origin at x, 0, 0		Along [010]   p2
a' = c   b' = a   
Origin at 0, y, 0

Maximal non-isomorphic subgroups

I [2] P1 (1)1
IIa none
IIb[2] P1211 (b' = 2b) (P21, 4); [2] C121 (a' = 2a, b' = 2b) (C2, 5); [2] A121 (b' = 2b, c' = 2c) (C2, 5); [2] F121 (a' = 2a, b' = 2b, c' = 2c) (C2, 5)

Maximal isomorphic subgroups of lowest index

IIc[2] P121 (b' = 2b) (P2, 3); [2] P121 (c' = 2c or a' = 2a or a' = a + c, c' = -a + c) (P2, 3)

Minimal non-isomorphic supergroups

I[2] P2/m (10); [2] P2/c (13); [2] P222 (16); [2] P2221 (17); [2] P21212 (18); [2] C222 (21); [2] Pmm2 (25); [2] Pcc2 (27); [2] Pma2 (28); [2] Pnc2 (30); [2] Pba2 (32); [2] Pnn2 (34); [2] Cmm2 (35); [2] Ccc2 (37); [2] P4 (75); [2] P42 (77); [2] P-4 (81); [3] P6 (168); [3] P62 (171); [3] P64 (172)
II[2] C121 (C2, 5); [2] A121 (C2, 5); [2] I121 (C2, 5)








































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