Origin at 2 3, at -1/4, -1/4, -1/4 from centre (-3)
Asymmetric unit | 0 ≤ x ≤ 1; 0 ≤ y ≤ 1/2; 0 ≤ z ≤ 1/2; y ≤ min(x, 1 - x); z ≤ y |
Vertices | 0, 0, 0 | 1, 0, 0 | 1/2, 1/2, 0 | 1/2, 1/2, 1/2 |
|
(1) 1 | (2) 2 0, 0, z | (3) 2 0, y, 0 | (4) 2 x, 0, 0 |
(5) 3+ x, x, x | (6) 3+ -x, x, -x | (7) 3+ x, -x, -x | (8) 3+ -x, -x, x |
(9) 3- x, x, x | (10) 3- x, -x, -x | (11) 3- -x, -x, x | (12) 3- -x, x, -x |
(13) -1 1/4, 1/4, 1/4 | (14) n(1/2, 1/2, 0) x, y, 1/4 | (15) n(1/2, 0, 1/2) x, 1/4, z | (16) n(0, 1/2, 1/2) 1/4, y, z |
(17) -3+ x, x, x; 1/4, 1/4, 1/4 | (18) -3+ -x - 1, x + 1, -x; -1/4, 1/4, 3/4 | (19) -3+ x, -x + 1, -x; 1/4, 3/4, -1/4 | (20) -3+ -x + 1, -x, x; 3/4, -1/4, 1/4 |
(21) -3- x, x, x; 1/4, 1/4, 1/4 | (22) -3- x + 1, -x - 1, -x; 1/4, -1/4, 3/4 | (23) -3- -x, -x + 1, x; -1/4, 3/4, 1/4 | (24) -3- -x + 1, x, -x; 3/4, 1/4, -1/4 |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); (2); (3); (5); (13)
Multiplicity, Wyckoff letter, Site symmetry | Coordinates | Reflection conditions |
| | h, k, l cyclically permutable General:
|
| (1) x, y, z | (2) -x, -y, z | (3) -x, y, -z | (4) x, -y, -z | (5) z, x, y | (6) z, -x, -y | (7) -z, -x, y | (8) -z, x, -y | (9) y, z, x | (10) -y, z, -x | (11) y, -z, -x | (12) -y, -z, x | (13) -x + 1/2, -y + 1/2, -z + 1/2 | (14) x + 1/2, y + 1/2, -z + 1/2 | (15) x + 1/2, -y + 1/2, z + 1/2 | (16) -x + 1/2, y + 1/2, z + 1/2 | (17) -z + 1/2, -x + 1/2, -y + 1/2 | (18) -z + 1/2, x + 1/2, y + 1/2 | (19) z + 1/2, x + 1/2, -y + 1/2 | (20) z + 1/2, -x + 1/2, y + 1/2 | (21) -y + 1/2, -z + 1/2, -x + 1/2 | (22) y + 1/2, -z + 1/2, x + 1/2 | (23) -y + 1/2, z + 1/2, x + 1/2 | (24) y + 1/2, z + 1/2, -x + 1/2 |
| 0kl : k + l = 2n h00 : h = 2n
|
| | Special: as above, plus
|
| x, 1/2, 0 | -x, 1/2, 0 | 0, x, 1/2 | 0, -x, 1/2 | 1/2, 0, x | 1/2, 0, -x | -x + 1/2, 0, 1/2 | x + 1/2, 0, 1/2 | 1/2, -x + 1/2, 0 | 1/2, x + 1/2, 0 | 0, 1/2, -x + 1/2 | 0, 1/2, x + 1/2 |
| hkl : h + k + l = 2n
|
| x, 0, 0 | -x, 0, 0 | 0, x, 0 | 0, -x, 0 | 0, 0, x | 0, 0, -x | -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 | 1/2, 1/2, -x + 1/2 | 1/2, 1/2, x + 1/2 |
| hkl : h + k + l = 2n
|
| x, x, x | -x, -x, x | -x, x, -x | x, -x, -x | -x + 1/2, -x + 1/2, -x + 1/2 | x + 1/2, x + 1/2, -x + 1/2 | x + 1/2, -x + 1/2, x + 1/2 | -x + 1/2, x + 1/2, x + 1/2 |
| no extra conditions |
| 0, 1/2, 1/2 | 1/2, 0, 1/2 | 1/2, 1/2, 0 | 1/2, 0, 0 | 0, 1/2, 0 | 0, 0, 1/2 |
| hkl : h + k + l = 2n
|
| 3/4, 3/4, 3/4 | 1/4, 1/4, 3/4 | 1/4, 3/4, 1/4 | 3/4, 1/4, 1/4 |
| hkl : h + k, h + l, k + l = 2n
|
| 1/4, 1/4, 1/4 | 3/4, 3/4, 1/4 | 3/4, 1/4, 3/4 | 1/4, 3/4, 3/4 |
| hkl : h + k, h + l, k + l = 2n
|
| | hkl : h + k + l = 2n
|
Symmetry of special projections
Along [001] c2mm a' = a b' = b Origin at 0, 0, z | Along [111] p6 a' = 1/3(2a - b - c) b' = 1/3(-a + 2b - c) Origin at x, x, x | Along [110] p2mm a' = 1/2(-a + b) b' = c Origin at x, x, 1/4 |
Maximal non-isomorphic subgroups
I | | [2] P23 (195) | 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12 |
| | [3] Pn1 (Pnnn, 48) | 1; 2; 3; 4; 13; 14; 15; 16 |
| | [4] P1-3 (R-3, 148) | 1; 5; 9; 13; 17; 21 | | [4] P1-3 (R-3, 148) | 1; 6; 12; 13; 18; 24 | | [4] P1-3 (R-3, 148) | 1; 7; 10; 13; 19; 22 | | [4] P1-3 (R-3, 148) | 1; 8; 11; 13; 20; 23 |
|
IIb | [2] Fd-3 (a' = 2a, b' = 2b, c' = 2c) (203) |
Maximal isomorphic subgroups of lowest index
IIc | [27] Pn-3 (a' = 3a, b' = 3b, c' = 3c) (201) |
Minimal non-isomorphic supergroups
I | [2] Pn-3n (222); [2] Pn-3m (224) |
II | [2] Im-3 (204); [4] Fm-3 (202) |
Origin at centre (-3), at 1/4, 1/4, 1/4 from 2 3
Asymmetric unit | -1/4 ≤ x ≤ 3/4; -1/4 ≤ y ≤ 1/4; -1/4 ≤ z ≤ 1/4; y ≤ min(x, 1/2 - x); z ≤ y |
Vertices | -1/4, -1/4, -1/4 | 3/4, -1/4, -1/4 | 1/4, 1/4, -1/4 | 1/4, 1/4, 1/4 |
|
(1) 1 | (2) 2 1/4, 1/4, z | (3) 2 1/4, y, 1/4 | (4) 2 x, 1/4, 1/4 |
(5) 3+ x, x, x | (6) 3+ -x, x + 1/2, -x | (7) 3+ x + 1/2, -x, -x | (8) 3+ -x + 1/2, -x + 1/2, x |
(9) 3- x, x, x | (10) 3- x + 1/2, -x, -x | (11) 3- -x + 1/2, -x + 1/2, x | (12) 3- -x, x + 1/2, -x |
(13) -1 0, 0, 0 | (14) n(1/2, 1/2, 0) x, y, 0 | (15) n(1/2, 0, 1/2) x, 0, z | (16) n(0, 1/2, 1/2) 0, y, z |
(17) -3+ x, x, x; 0, 0, 0 | (18) -3+ -x - 1, x + 1/2, -x; -1/2, 0, 1/2 | (19) -3+ x - 1/2, -x + 1, -x; 0, 1/2, -1/2 | (20) -3+ -x + 1/2, -x - 1/2, x; 1/2, -1/2, 0 |
(21) -3- x, x, x; 0, 0, 0 | (22) -3- x + 1/2, -x - 1, -x; 0, -1/2, 1/2 | (23) -3- -x - 1/2, -x + 1/2, x; -1/2, 1/2, 0 | (24) -3- -x + 1, x - 1/2, -x; 1/2, 0, -1/2 |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); (2); (3); (5); (13)
Multiplicity, Wyckoff letter, Site symmetry | Coordinates | Reflection conditions |
| | h, k, l cyclically permutable General:
|
| (1) x, y, z | (2) -x + 1/2, -y + 1/2, z | (3) -x + 1/2, y, -z + 1/2 | (4) x, -y + 1/2, -z + 1/2 | (5) z, x, y | (6) z, -x + 1/2, -y + 1/2 | (7) -z + 1/2, -x + 1/2, y | (8) -z + 1/2, x, -y + 1/2 | (9) y, z, x | (10) -y + 1/2, z, -x + 1/2 | (11) y, -z + 1/2, -x + 1/2 | (12) -y + 1/2, -z + 1/2, x | (13) -x, -y, -z | (14) x + 1/2, y + 1/2, -z | (15) x + 1/2, -y, z + 1/2 | (16) -x, y + 1/2, z + 1/2 | (17) -z, -x, -y | (18) -z, x + 1/2, y + 1/2 | (19) z + 1/2, x + 1/2, -y | (20) z + 1/2, -x, y + 1/2 | (21) -y, -z, -x | (22) y + 1/2, -z, x + 1/2 | (23) -y, z + 1/2, x + 1/2 | (24) y + 1/2, z + 1/2, -x |
| 0kl : k + l = 2n h00 : h = 2n
|
| | Special: as above, plus
|
| x, 3/4, 1/4 | -x + 1/2, 3/4, 1/4 | 1/4, x, 3/4 | 1/4, -x + 1/2, 3/4 | 3/4, 1/4, x | 3/4, 1/4, -x + 1/2 | -x, 1/4, 3/4 | x + 1/2, 1/4, 3/4 | 3/4, -x, 1/4 | 3/4, x + 1/2, 1/4 | 1/4, 3/4, -x | 1/4, 3/4, x + 1/2 |
| hkl : h + k + l = 2n
|
| x, 1/4, 1/4 | -x + 1/2, 1/4, 1/4 | 1/4, x, 1/4 | 1/4, -x + 1/2, 1/4 | 1/4, 1/4, x | 1/4, 1/4, -x + 1/2 | -x, 3/4, 3/4 | x + 1/2, 3/4, 3/4 | 3/4, -x, 3/4 | 3/4, x + 1/2, 3/4 | 3/4, 3/4, -x | 3/4, 3/4, x + 1/2 |
| hkl : h + k + l = 2n
|
| x, x, x | -x + 1/2, -x + 1/2, x | -x + 1/2, x, -x + 1/2 | x, -x + 1/2, -x + 1/2 | -x, -x, -x | x + 1/2, x + 1/2, -x | x + 1/2, -x, x + 1/2 | -x, x + 1/2, x + 1/2 |
| no extra conditions |
| 1/4, 3/4, 3/4 | 3/4, 1/4, 3/4 | 3/4, 3/4, 1/4 | 3/4, 1/4, 1/4 | 1/4, 3/4, 1/4 | 1/4, 1/4, 3/4 |
| hkl : h + k + l = 2n
|
| 1/2, 1/2, 1/2 | 0, 0, 1/2 | 0, 1/2, 0 | 1/2, 0, 0 |
| hkl : h + k, h + l, k + l = 2n
|
| 0, 0, 0 | 1/2, 1/2, 0 | 1/2, 0, 1/2 | 0, 1/2, 1/2 |
| hkl : h + k, h + l, k + l = 2n
|
| 1/4, 1/4, 1/4 | 3/4, 3/4, 3/4 |
| hkl : h + k + l = 2n
|
Symmetry of special projections
Along [001] c2mm a' = a b' = b Origin at 1/4, 1/4, z | Along [111] p6 a' = 1/3(2a - b - c) b' = 1/3(-a + 2b - c) Origin at x, x, x | Along [110] p2mm a' = 1/2(-a + b) b' = c Origin at x, x, 0 |
Maximal non-isomorphic subgroups
I | | [2] P23 (195) | 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12 |
| | [3] Pn1 (Pnnn, 48) | 1; 2; 3; 4; 13; 14; 15; 16 |
| | [4] P1-3 (R-3, 148) | 1; 5; 9; 13; 17; 21 | | [4] P1-3 (R-3, 148) | 1; 6; 12; 13; 18; 24 | | [4] P1-3 (R-3, 148) | 1; 7; 10; 13; 19; 22 | | [4] P1-3 (R-3, 148) | 1; 8; 11; 13; 20; 23 |
|
IIb | [2] Fd-3 (a' = 2a, b' = 2b, c' = 2c) (203) |
Maximal isomorphic subgroups of lowest index
IIc | [27] Pn-3 (a' = 3a, b' = 3b, c' = 3c) (201) |
Minimal non-isomorphic supergroups
I | [2] Pn-3n (222); [2] Pn-3m (224) |
II | [2] Im-3 (204); [4] Fm-3 (202) |