| P21 | C22 | 2 | Monoclinic  |
| No. 4 | P1211 | Patterson symmetry P12/m1 | |
| UNIQUE AXIS b | |||
Origin on 21
| Asymmetric unit | 0 ≤ x ≤ 1; 0 ≤ y ≤ 1; 0 ≤ z ≤ 1/2 |
Symmetry operations
| (1) 1 | (2) 2(0, 1/2, 0) 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: | ||||||||
|
| 0k0 : k = 2n |
Symmetry of special projections
| Along [001] p1g1 a' = ap b' = b Origin at 0, 0, z | Along [100] p11g 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 | none |
Maximal isomorphic subgroups of lowest index
| IIc | [2] P1211 (c' = 2c or a' = 2a or a' = a + c, c' = -a + c) (P21, 4); [3] P1211 (b' = 3b) (P21, 4) |
Minimal non-isomorphic supergroups
| I | [2] P21/m (11); [2] P21/c (14); [2] P2221 (17); [2] P21212 (18); [2] P212121 (19); [2] C2221 (20); [2] Pmc21 (26); [2] Pca21 (29); [2] Pmn21 (31); [2] Pna21 (33); [2] Cmc21 (36); [2] P41 (76); [2] P43 (78); [3] P61 (169); [3] P65 (170); [3] P63 (173) |
| II | [2] C121 (C2, 5); [2] A121 (C2, 5); [2] I121 (C2, 5); [2] P121 (b' = 1/2b) (P2, 3) |
