Origin at centre (2/m) at 2/m n 1
| Asymmetric unit | 0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1; 0 ≤ z ≤ 1/4 |
| (1) 1 | (2) 2(0, 0, 1/2) 1/4, 0, z | (3) 2 1/4, y, 1/4 | (4) 2 x, 0, 0 |
| (5) -1 0, 0, 0 | (6) a x, y, 1/4 | (7) n(1/2, 0, 1/2) x, 0, z | (8) m 0, y, z |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); (2); (3); (5)
Multiplicity, Wyckoff letter,
Site symmetry | Coordinates | Reflection conditions |
| | | General:
|
| | (1) x, y, z | (2) -x + 1/2, -y, z + 1/2 | (3) -x + 1/2, y, -z + 1/2 | (4) x, -y, -z | | (5) -x, -y, -z | (6) x + 1/2, y, -z + 1/2 | (7) x + 1/2, -y, z + 1/2 | (8) -x, y, z |
| h0l : h + l = 2n
hk0 : h = 2n
h00 : h = 2n
00l : l = 2n
|
| | | Special: as above, plus
|
| | 0, y, z | 1/2, -y, z + 1/2 | 1/2, y, -z + 1/2 | 0, -y, -z |
| no extra conditions |
| | 1/4, y, 1/4 | 1/4, -y, 3/4 | 3/4, -y, 3/4 | 3/4, y, 1/4 |
| hkl : h = 2n
|
| | x, 1/2, 0 | -x + 1/2, 1/2, 1/2 | -x, 1/2, 0 | x + 1/2, 1/2, 1/2 |
| hkl : h + l = 2n
|
| | x, 0, 0 | -x + 1/2, 0, 1/2 | -x, 0, 0 | x + 1/2, 0, 1/2 |
| hkl : h + l = 2n
|
| | hkl : h + l = 2n
|
| | hkl : h + l = 2n
|
| | hkl : h + l = 2n
|
| | hkl : h + l = 2n
|
Symmetry of special projections
Along [001] p2mm
a' = 1/2a b' = b
Origin at 0, 0, z | Along [100] p2gm
a' = b b' = c
Origin at x, 0, 0 | Along [010] c2mm
a' = c b' = a
Origin at 0, y, 0 |
Maximal non-isomorphic subgroups
| I | | [2] Pmn21 (31) | 1; 2; 7; 8 |
| | | [2] P2na (Pnc2, 30) | 1; 4; 6; 7 |
| | | [2] Pm2a (Pma2, 28) | 1; 3; 6; 8 |
| | | [2] P2221 (17) | 1; 2; 3; 4 |
| | | [2] P1121/a (P21/c, 14) | 1; 2; 5; 6 |
| | | [2] P12/n1 (P2/c, 13) | 1; 3; 5; 7 |
| | | [2] P2/m11 (P2/m, 10) | 1; 4; 5; 8 |
| IIb | [2] Pbna (b' = 2b) (Pbcn, 60); [2] Pmnn (b' = 2b) (Pnnm, 58); [2] Pbnn (b' = 2b) (Pnna, 52) |
Maximal isomorphic subgroups of lowest index
| IIc | [2] Pmna (b' = 2b) (53); [3] Pmna (a' = 3a) (53); [3] Pmna (c' = 3c) (53) |
Minimal non-isomorphic supergroups
| II | [2] Cmce (64); [2] Bmmm (Cmmm, 65); [2] Amaa (Cccm, 66); [2] Imma (74); [2] Pmaa (c' = 1/2c) (Pccm, 49); [2] Pmcm (a' = 1/2a) (Pmma, 51) |
