Pcc2 C2v3 mm2 Orthorhombic No. 27 Pcc2 Patterson symmetry Pmmm

Origin on c c 2

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

Symmetry operations

 (1)  1 (2)  2   0, 0, z (3)  c   x, 0, z (4)  c   0, 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 e 1
 (1) x, y, z (2) -x, -y, z (3) x, -y, z + 1/2 (4) -x, y, z + 1/2
0kl : l = 2n
h0l : l = 2n
00l : l = 2n
Special: as above, plus
 2 d . . 2
 1/2, 1/2, z 1/2, 1/2, z + 1/2
hkl : l = 2n
 2 c . . 2
 1/2, 0, z 1/2, 0, z + 1/2
hkl : l = 2n
 2 b . . 2
 0, 1/2, z 0, 1/2, z + 1/2
hkl : l = 2n
 2 a . . 2
 0, 0, z 0, 0, z + 1/2
hkl : l = 2n

Symmetry of special projections

 Along [001]   p2mma' = a   b' = b   Origin at 0, 0, z Along [100]   p1m1a' = b   b' = 1/2c   Origin at x, 0, 0 Along [010]   p11ma' = 1/2c   b' = a   Origin at 0, y, 0

Maximal non-isomorphic subgroups

 I [2] P1c1 (Pc, 7) 1; 3 [2] Pc11 (Pc, 7) 1; 4 [2] P112 (P2, 3) 1; 2
 IIa none
 IIb [2] Pcn2 (a' = 2a) (Pnc2, 30); [2] Pnc2 (b' = 2b) (30); [2] Ccc2 (a' = 2a, b' = 2b) (37)

Maximal isomorphic subgroups of lowest index

 IIc [2] Pcc2 (a' = 2a or b' = 2b) (27); [3] Pcc2 (c' = 3c) (27)

Minimal non-isomorphic supergroups

 I [2] Pccm (49); [2] Pcca (54); [2] Pccn (56); [2] P42cm (101); [2] P4cc (103); [2] P-4c2 (116)
 II [2] Ccc2 (37); [2] Aem2 (39); [2] Bme2 (Aem2, 39); [2] Iba2 (45); [2] Pmm2 (c' = 1/2c) (25)