Origin at centre (2/m) at 42/m 1 n
Asymmetric unit | 0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1/2; 0 ≤ z ≤ 1/4 |
Symmetry operations
(1) 1 | (2) 2 0, 0, z | (3) 4+(0, 0, 1/2) 0, 0, z | (4) 4-(0, 0, 1/2) 0, 0, z |
(5) 2(0, 1/2, 0) 1/4, y, 0 | (6) 2(1/2, 0, 0) x, 1/4, 0 | (7) 2(1/2, 1/2, 0) x, x, 1/4 | (8) 2 x, -x + 1/2, 1/4 |
(9) -1 0, 0, 0 | (10) m x, y, 0 | (11) -4+ 0, 0, z; 0, 0, 1/4 | (12) -4- 0, 0, z; 0, 0, 1/4 |
(13) a x, 1/4, z | (14) b 1/4, y, z | (15) c x + 1/2, -x, z | (16) n(1/2, 1/2, 1/2) x, x, z |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); (2); (3); (5); (9)
Positions
Multiplicity, Wyckoff letter, Site symmetry | Coordinates | Reflection conditions | |||||||||||||||||||
General: | |||||||||||||||||||||
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| 0kl : k = 2n hhl : l = 2n 00l : l = 2n h00 : h = 2n |
Special: as above, plus | |||||||||||||
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| no extra conditions | |||||||||||
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| hkl : l = 2n | |||||||||||
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| hkl : h + k, l = 2n | |||||||||||
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| hkl : h + k, l = 2n | |||||||||||
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| hkl : h + k, l = 2n | |||||||||||
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| hkl : h + k, l = 2n | |||||||||||
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| hkl : h + k, l = 2n | |||||||||||
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| hkl : h + k, l = 2n |
Symmetry of special projections
Along [001] p4gm a' = a b' = 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' = 1/2c Origin at x, x, 0 |
Maximal non-isomorphic subgroups
I | [2] P-4b2 (117) | 1; 2; 7; 8; 11; 12; 13; 14 | |
[2] P-421c (114) | 1; 2; 5; 6; 11; 12; 15; 16 | ||
[2] P42bc (106) | 1; 2; 3; 4; 13; 14; 15; 16 | ||
[2] P42212 (94) | 1; 2; 3; 4; 5; 6; 7; 8 | ||
[2] P42/m11 (P42/m, 84) | 1; 2; 3; 4; 9; 10; 11; 12 | ||
[2] P2/m12/c (Cccm, 66) | 1; 2; 7; 8; 9; 10; 15; 16 | ||
[2] P2/m21/b1 (Pbam, 55) | 1; 2; 5; 6; 9; 10; 13; 14 |
IIa | none |
IIb | none |
Maximal isomorphic subgroups of lowest index
IIc | [3] P42/mbc (c' = 3c) (135); [9] P42/mbc (a' = 3a, b' = 3b) (135) |
Minimal non-isomorphic supergroups
I | none |
II | [2] C42/mmc (P42/mcm, 132); [2] I4/mcm (140); [2] P4/mbm (c' = 1/2c) (127) |