| Cm | Cs3 | m | Monoclinic  |
| No. 8 | C1m1 | Patterson symmetry C12/m1 | |
| UNIQUE AXIS b, CELL CHOICE 1 | |||
Origin on mirror plane m
| Asymmetric unit | 0 ≤ x ≤ 1; 0 ≤ y ≤ 1/4; 0 ≤ z ≤ 1 |
Symmetry operations
For (0, 0, 0)+ set
| (1) 1 | (2) m x, 0, z |
For (1/2, 1/2, 0)+ set
| (1) t(1/2, 1/2, 0) | (2) a x, 1/4, z |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); t(1/2, 1/2, 0); (2)
Positions
| Multiplicity, Wyckoff letter, Site symmetry | Coordinates | Reflection conditions | |||||
| (0, 0, 0)+ (1/2, 1/2, 0)+ | General: | ||||||
|
| hkl : h + k = 2n h0l : h = 2n 0kl : k = 2n hk0 : h + k = 2n 0k0 : k = 2n h00 : h = 2n |
| Special: as above, plus | ||||||
|
| no extra conditions |
Symmetry of special projections
| Along [001] c11m a' = ap b' = b Origin at 0, 0, z | Along [100] p1m1 a' = 1/2b b' = cp Origin at x, 0, 0 | Along [010] p1 a' = c b' = 1/2a Origin at 0, y, 0 |
Maximal non-isomorphic subgroups
| I | [2] C1 (P1, 1) | 1+ |
| IIa | [2] P1a1 (Pc, 7) | 1; 2 + (1/2, 1/2, 0) | |
| [2] P1m1 (Pm, 6) | 1; 2 |
| IIb | [2] C1c1 (c' = 2c) (Cc, 9); [2] I1c1 (c' = 2c) (Cc, 9) |
Maximal isomorphic subgroups of lowest index
| IIc | [2] C1m1 (c' = 2c or a' = a + 2c, c' = 2c) (Cm, 8); [3] C1m1 (b' = 3b) (Cm, 8) |
Minimal non-isomorphic supergroups
| I | [2] C2/m (12); [2] Cmm2 (35); [2] Cmc21 (36); [2] Amm2 (38); [2] Aem2 (39); [2] Fmm2 (42); [2] Imm2 (44); [2] Ima2 (46); [3] P3m1 (156); [3] P31m (157); [3] R3m (160) |
| II | [2] P1m1 (a' = 1/2a, b' = 1/2b) (Pm, 6) |
UNIQUE AXIS b, DIFFERENT CELL CHOICES
C1m1
UNIQUE AXIS b, CELL CHOICE 1
Origin on mirror plane m
| Asymmetric unit | 0 ≤ x ≤ 1; 0 ≤ y ≤ 1/4; 0 ≤ z ≤ 1 |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); t(1/2, 1/2, 0); (2)
Positions
| Multiplicity, Wyckoff letter, Site symmetry | Coordinates | Reflection conditions | |||||
| (0, 0, 0)+ (1/2, 1/2, 0)+ | General: | ||||||
|
| hkl : h + k = 2n h0l : h = 2n 0kl : k = 2n hk0 : h + k = 2n 0k0 : k = 2n h00 : h = 2n |
| Special: as above, plus | ||||||
|
| no extra conditions |
A1m1
UNIQUE AXIS b, CELL CHOICE 2
Origin on mirror plane m
| Asymmetric unit | 0 ≤ x ≤ 1; 0 ≤ y ≤ 1/4; 0 ≤ z ≤ 1 |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); t(0, 1/2, 1/2); (2)
Positions
| Multiplicity, Wyckoff letter, Site symmetry | Coordinates | Reflection conditions | |||||
| (0, 0, 0)+ (0, 1/2, 1/2)+ | General: | ||||||
|
| hkl : k + l = 2n h0l : l = 2n 0kl : k + l = 2n hk0 : k = 2n 0k0 : k = 2n 00l : l = 2n |
| Special: as above, plus | ||||||
|
| no extra conditions |
I1m1
UNIQUE AXIS b, CELL CHOICE 3
Origin on mirror plane m
| Asymmetric unit | 0 ≤ x ≤ 1; 0 ≤ y ≤ 1/4; 0 ≤ z ≤ 1 |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); t(1/2, 1/2, 1/2); (2)
Positions
| Multiplicity, Wyckoff letter, Site symmetry | Coordinates | Reflection conditions | |||||
| (0, 0, 0)+ (1/2, 1/2, 1/2)+ | General: | ||||||
|
| hkl : h + k + l = 2n h0l : h + l = 2n 0kl : k + l = 2n hk0 : h + k = 2n 0k0 : k = 2n h00 : h = 2n 00l : l = 2n |
| Special: as above, plus | ||||||
|
| no extra conditions |
