Pba2 C2v8 mm2 Orthorhombic info
No. 32 Pba2 Patterson symmetry Pmmm

symmetry group diagram

Origin on 1 1 2

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

Symmetry operations

(1)  1   (2)  2   0, 0, z(3)  a   x, 1/4, z(4)  b   1/4, y, z

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

Positions

Multiplicity, Wyckoff letter,
Site symmetry		 Coordinates Reflection conditions
 General:
4 c 1
(1) x, y, z(2) -x, -y, z(3) x + 1/2, -y + 1/2, z(4) -x + 1/2, y + 1/2, z
0kl : k = 2n
h0l : h = 2n
h00 : h = 2n
0k0 : k = 2n
    Special: as above, plus
2 b  . . 2 
0, 1/2, z 1/2, 0, z
hkl : h + k = 2n
2 a  . . 2 
0, 0, z 1/2, 1/2, z
hkl : h + k = 2n

Symmetry of special projections

Along [001]   p2gg
a' = a   b' = b   
Origin at 0, 0, z		Along [100]   p1m1
a' = 1/2b   b' = c   
Origin at x, 0, 0		Along [010]   p11m
a' = c   b' = 1/2a   
Origin at 0, y, 0

Maximal non-isomorphic subgroups

I [2] P1a1 (Pc, 7)1; 3
  [2] Pb11 (Pc, 7)1; 4
  [2] P112 (P2, 3)1; 2
IIa none
IIb[2] Pnn2 (c' = 2c) (34); [2] Pna21 (c' = 2c) (33); [2] Pbn21 (c' = 2c) (Pna21, 33)

Maximal isomorphic subgroups of lowest index

IIc[2] Pba2 (c' = 2c) (32); [3] Pba2 (a' = 3a or b' = 3b) (32)

Minimal non-isomorphic supergroups

I[2] Pban (50); [2] Pcca (54); [2] Pbam (55); [2] P4bm (100); [2] P42bc (106); [2] P-4b2 (117)
II[2] Cmm2 (35); [2] Aea2 (41); [2] Bbe2 (Aea2, 41); [2] Iba2 (45); [2] Pbm2 (a' = 1/2a) (Pma2, 28); [2] Pma2 (b' = 1/2b) (28)








































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