| Pna21 | C2v9 | mm2 | Orthorhombic  |
| No. 33 | Pna21 | Patterson symmetry Pmmm | |
Origin on 1 1 21
| Asymmetric unit | 0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1/2; 0 ≤ z ≤ 1 |
Symmetry operations
| (1) 1 | (2) 2(0, 0, 1/2) 0, 0, z | (3) a x, 1/4, z | (4) n(0, 1/2, 1/2) 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: | |||||||||
|
| 0kl : k + l = 2n h0l : h = 2n h00 : h = 2n 0k0 : k = 2n 00l : l = 2n |
Symmetry of special projections
| Along [001] p2gg a' = a b' = b Origin at 0, 0, z | Along [100] c1m1 a' = b b' = c Origin at x, 1/4, 0 | Along [010] p11g a' = c b' = 1/2a Origin at 0, y, 0 |
Maximal non-isomorphic subgroups
| I | [2] P1a1 (Pc, 7) | 1; 3 | |
| [2] Pn11 (Pc, 7) | 1; 4 | ||
| [2] P1121 (P21, 4) | 1; 2 |
| IIa | none |
| IIb | none |
Maximal isomorphic subgroups of lowest index
| IIc | [3] Pna21 (a' = 3a) (33); [3] Pna21 (b' = 3b) (33); [3] Pna21 (c' = 3c) (33) |
Minimal non-isomorphic supergroups
| I | [2] Pnna (52); [2] Pccn (56); [2] Pbcn (60); [2] Pnma (62) |
| II | [2] Ccm21 (Cmc21, 36); [2] Ama2 (40); [2] Bbe2 (Aea2, 41); [2] Ima2 (46); [2] Pca21 (b' = 1/2b) (29); [2] Pnm21 (a' = 1/2a) (Pmn21, 31); [2] Pba2 (c' = 1/2c) (32) |
