Origin at 4 2 2 at 4/n 2 2/g, at -1/4, -1/4, 0 from centre (2/m)
Asymmetric unit | 0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1/2; 0 ≤ z ≤ 1/2; y ≤ 1/2 - x |
(1) 1 | (2) 2 0, 0, z | (3) 4+ 0, 0, z | (4) 4- 0, 0, z |
(5) 2 0, y, 0 | (6) 2 x, 0, 0 | (7) 2 x, x, 0 | (8) 2 x, -x, 0 |
(9) -1 1/4, 1/4, 0 | (10) n(1/2, 1/2, 0) x, y, 0 | (11) -4+ 1/2, 0, z; 1/2, 0, 0 | (12) -4- 0, 1/2, z; 0, 1/2, 0 |
(13) a x, 1/4, z | (14) b 1/4, y, z | (15) m x + 1/2, -x, z | (16) g(1/2, 1/2, 0) x, x, z |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); (2); (3); (5); (9)
Multiplicity, Wyckoff letter, Site symmetry | Coordinates | Reflection conditions |
| | General:
|
| (1) x, y, z | (2) -x, -y, z | (3) -y, x, z | (4) y, -x, z | (5) -x, y, -z | (6) x, -y, -z | (7) y, x, -z | (8) -y, -x, -z | (9) -x + 1/2, -y + 1/2, -z | (10) x + 1/2, y + 1/2, -z | (11) y + 1/2, -x + 1/2, -z | (12) -y + 1/2, x + 1/2, -z | (13) x + 1/2, -y + 1/2, z | (14) -x + 1/2, y + 1/2, z | (15) -y + 1/2, -x + 1/2, z | (16) y + 1/2, x + 1/2, z |
| hk0 : h + k = 2n 0kl : k = 2n h00 : h = 2n
|
| | Special: as above, plus
|
| x, x + 1/2, z | -x, -x + 1/2, z | -x + 1/2, x, z | x + 1/2, -x, z | -x, x + 1/2, -z | x, -x + 1/2, -z | x + 1/2, x, -z | -x + 1/2, -x, -z |
| no extra conditions |
| x, 0, 1/2 | -x, 0, 1/2 | 0, x, 1/2 | 0, -x, 1/2 | -x + 1/2, 1/2, 1/2 | x + 1/2, 1/2, 1/2 | 1/2, -x + 1/2, 1/2 | 1/2, x + 1/2, 1/2 |
| hkl : h + k = 2n
|
| x, 0, 0 | -x, 0, 0 | 0, x, 0 | 0, -x, 0 | -x + 1/2, 1/2, 0 | x + 1/2, 1/2, 0 | 1/2, -x + 1/2, 0 | 1/2, x + 1/2, 0 |
| hkl : h + k = 2n
|
| x, x, 1/2 | -x, -x, 1/2 | -x, x, 1/2 | x, -x, 1/2 | -x + 1/2, -x + 1/2, 1/2 | x + 1/2, x + 1/2, 1/2 | x + 1/2, -x + 1/2, 1/2 | -x + 1/2, x + 1/2, 1/2 |
| hkl : h + k = 2n
|
| x, x, 0 | -x, -x, 0 | -x, x, 0 | x, -x, 0 | -x + 1/2, -x + 1/2, 0 | x + 1/2, x + 1/2, 0 | x + 1/2, -x + 1/2, 0 | -x + 1/2, x + 1/2, 0 |
| hkl : h + k = 2n
|
| 0, 1/2, z | 1/2, 0, z | 0, 1/2, -z | 1/2, 0, -z |
| hkl : h + k = 2n
|
| 0, 0, z | 0, 0, -z | 1/2, 1/2, -z | 1/2, 1/2, z |
| hkl : h + k = 2n
|
| 1/4, 1/4, 1/2 | 3/4, 3/4, 1/2 | 3/4, 1/4, 1/2 | 1/4, 3/4, 1/2 |
| hkl : h, k = 2n
|
| 1/4, 1/4, 0 | 3/4, 3/4, 0 | 3/4, 1/4, 0 | 1/4, 3/4, 0 |
| hkl : h, k = 2n
|
| | hkl : h + k = 2n
|
| | hkl : h + k = 2n
|
| | hkl : h + k = 2n
|
| | hkl : h + k = 2n
|
Symmetry of special projections
Along [001] p4mm a' = 1/2(a - b) b' = 1/2(a + b) Origin at 0, 0, z | Along [100] p2mm a' = 1/2b b' = c Origin at x, 0, 0 | Along [110] p2mm a' = 1/2(-a + b) b' = c Origin at x, x, 0 |
Maximal non-isomorphic subgroups
I | | [2] P-4b2 (117) | 1; 2; 7; 8; 11; 12; 13; 14 |
| | [2] P-42m (111) | 1; 2; 5; 6; 11; 12; 15; 16 |
| | [2] P4bm (100) | 1; 2; 3; 4; 13; 14; 15; 16 |
| | [2] P422 (89) | 1; 2; 3; 4; 5; 6; 7; 8 |
| | [2] P4/n11 (P4/n, 85) | 1; 2; 3; 4; 9; 10; 11; 12 |
| | [2] P2/n12/m (Cmme, 67) | 1; 2; 7; 8; 9; 10; 15; 16 |
| | [2] P2/n2/b1 (Pban, 50) | 1; 2; 5; 6; 9; 10; 13; 14 |
IIb | [2] P42/nnm (c' = 2c) (134); [2] P42/nbc (c' = 2c) (133); [2] P4/nnc (c' = 2c) (126) |
Maximal isomorphic subgroups of lowest index
IIc | [2] P4/nbm (c' = 2c) (125); [9] P4/nbm (a' = 3a, b' = 3b) (125) |
Minimal non-isomorphic supergroups
II | [2] C4/mmm (P4/mmm, 123); [2] I4/mcm (140) |
Origin at centre (2/m) at n(b, a)(21/g, 2/m), at 1/4, 1/4, 0 from 4 2 2
Asymmetric unit | -1/4 ≤ x ≤ 1/4; -1/4 ≤ y ≤ 1/4; 0 ≤ z ≤ 1/2; x ≤ -y |
(1) 1 | (2) 2 1/4, 1/4, z | (3) 4+ 1/4, 1/4, z | (4) 4- 1/4, 1/4, z |
(5) 2 1/4, y, 0 | (6) 2 x, 1/4, 0 | (7) 2 x, x, 0 | (8) 2 x, -x + 1/2, 0 |
(9) -1 0, 0, 0 | (10) n(1/2, 1/2, 0) x, y, 0 | (11) -4+ 1/4, -1/4, z; 1/4, -1/4, 0 | (12) -4- -1/4, 1/4, z; -1/4, 1/4, 0 |
(13) a x, 0, z | (14) b 0, y, z | (15) m x, -x, z | (16) g(1/2, 1/2, 0) x, x, z |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); (2); (3); (5); (9)
Multiplicity, Wyckoff letter, Site symmetry | Coordinates | Reflection conditions |
| | General:
|
| (1) x, y, z | (2) -x + 1/2, -y + 1/2, z | (3) -y + 1/2, x, z | (4) y, -x + 1/2, z | (5) -x + 1/2, y, -z | (6) x, -y + 1/2, -z | (7) y, x, -z | (8) -y + 1/2, -x + 1/2, -z | (9) -x, -y, -z | (10) x + 1/2, y + 1/2, -z | (11) y + 1/2, -x, -z | (12) -y, x + 1/2, -z | (13) x + 1/2, -y, z | (14) -x, y + 1/2, z | (15) -y, -x, z | (16) y + 1/2, x + 1/2, z |
| hk0 : h + k = 2n 0kl : k = 2n h00 : h = 2n
|
| | Special: as above, plus
|
| x, -x, z | -x + 1/2, x + 1/2, z | x + 1/2, x, z | -x, -x + 1/2, z | -x + 1/2, -x, -z | x, x + 1/2, -z | -x, x, -z | x + 1/2, -x + 1/2, -z |
| no extra conditions |
| x, 1/4, 1/2 | -x + 1/2, 1/4, 1/2 | 1/4, x, 1/2 | 1/4, -x + 1/2, 1/2 | -x, 3/4, 1/2 | x + 1/2, 3/4, 1/2 | 3/4, -x, 1/2 | 3/4, x + 1/2, 1/2 |
| hkl : h + k = 2n
|
| x, 1/4, 0 | -x + 1/2, 1/4, 0 | 1/4, x, 0 | 1/4, -x + 1/2, 0 | -x, 3/4, 0 | x + 1/2, 3/4, 0 | 3/4, -x, 0 | 3/4, x + 1/2, 0 |
| hkl : h + k = 2n
|
| x, x, 1/2 | -x + 1/2, -x + 1/2, 1/2 | -x + 1/2, x, 1/2 | x, -x + 1/2, 1/2 | -x, -x, 1/2 | x + 1/2, x + 1/2, 1/2 | x + 1/2, -x, 1/2 | -x, x + 1/2, 1/2 |
| hkl : h + k = 2n
|
| x, x, 0 | -x + 1/2, -x + 1/2, 0 | -x + 1/2, x, 0 | x, -x + 1/2, 0 | -x, -x, 0 | x + 1/2, x + 1/2, 0 | x + 1/2, -x, 0 | -x, x + 1/2, 0 |
| hkl : h + k = 2n
|
| 3/4, 1/4, z | 1/4, 3/4, z | 3/4, 1/4, -z | 1/4, 3/4, -z |
| hkl : h + k = 2n
|
| 1/4, 1/4, z | 1/4, 1/4, -z | 3/4, 3/4, -z | 3/4, 3/4, z |
| hkl : h + k = 2n
|
| 0, 0, 1/2 | 1/2, 1/2, 1/2 | 1/2, 0, 1/2 | 0, 1/2, 1/2 |
| hkl : h, k = 2n
|
| 0, 0, 0 | 1/2, 1/2, 0 | 1/2, 0, 0 | 0, 1/2, 0 |
| hkl : h, k = 2n
|
| 3/4, 1/4, 1/2 | 1/4, 3/4, 1/2 |
| hkl : h + k = 2n
|
| | hkl : h + k = 2n
|
| 1/4, 1/4, 1/2 | 3/4, 3/4, 1/2 |
| hkl : h + k = 2n
|
| | hkl : h + k = 2n
|
Symmetry of special projections
Along [001] p4mm a' = 1/2(a - b) b' = 1/2(a + b) Origin at 1/4, 1/4, z | Along [100] p2mm a' = 1/2b b' = c Origin at x, 0, 0 | Along [110] p2mm a' = 1/2(-a + b) b' = c Origin at x, x, 0 |
Maximal non-isomorphic subgroups
I | | [2] P-4b2 (117) | 1; 2; 7; 8; 11; 12; 13; 14 |
| | [2] P-42m (111) | 1; 2; 5; 6; 11; 12; 15; 16 |
| | [2] P4bm (100) | 1; 2; 3; 4; 13; 14; 15; 16 |
| | [2] P422 (89) | 1; 2; 3; 4; 5; 6; 7; 8 |
| | [2] P4/n11 (P4/n, 85) | 1; 2; 3; 4; 9; 10; 11; 12 |
| | [2] P2/n12/m (Cmme, 67) | 1; 2; 7; 8; 9; 10; 15; 16 |
| | [2] P2/n2/b1 (Pban, 50) | 1; 2; 5; 6; 9; 10; 13; 14 |
IIb | [2] P42/nnm (c' = 2c) (134); [2] P42/nbc (c' = 2c) (133); [2] P4/nnc (c' = 2c) (126) |
Maximal isomorphic subgroups of lowest index
IIc | [2] P4/nbm (c' = 2c) (125); [9] P4/nbm (a' = 3a, b' = 3b) (125) |
Minimal non-isomorphic supergroups
II | [2] C4/mmm (P4/mmm, 123); [2] I4/mcm (140) |