Origin at 2 3
Asymmetric unit | 0 ≤ x ≤ 1/2; -1/8 ≤ y ≤ 1/8; -1/8 ≤ z ≤ 1/8; y ≤ min(x, 1/2 - x); -y ≤ z ≤ min(x, 1/2 - x) | ||||||||
Vertices |
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Symmetry operations
For (0, 0, 0)+ set
(1) 1 | (2) 2(0, 0, 1/2) 0, 1/4, z | (3) 2(0, 1/2, 0) 1/4, y, 0 | (4) 2(1/2, 0, 0) x, 0, 1/4 |
(5) 3+ x, x, x | (6) 3+(1/3, -1/3, 1/3) -x + 1/6, x + 1/6, -x | (7) 3+(-1/3, 1/3, 1/3) x + 1/3, -x - 1/6, -x | (8) 3+(1/3, 1/3, -1/3) -x + 1/6, -x + 1/3, x |
(9) 3- x, x, x | (10) 3- x, -x + 1/2, -x | (11) 3- -x + 1/2, -x, x | (12) 3- -x - 1/2, x + 1/2, -x |
(13) 2(1/2, 1/2, 0) x, x - 1/4, 3/8 | (14) 2 x, -x + 1/4, 1/8 | (15) 4-(0, 0, 3/4) 1/2, 1/4, z | (16) 4+(0, 0, 1/4) 0, 3/4, z |
(17) 4-(3/4, 0, 0) x, 1/2, 1/4 | (18) 2(0, 1/2, 1/2) 3/8, y + 1/4, y | (19) 2 1/8, y + 1/4, -y | (20) 4+(1/4, 0, 0) x, 0, 3/4 |
(21) 4+(0, 1/4, 0) 3/4, y, 0 | (22) 2(1/2, 0, 1/2) x - 1/4, 3/8, x | (23) 4-(0, 3/4, 0) 1/4, y, 1/2 | (24) 2 -x + 1/4, 1/8, x |
For (0, 1/2, 1/2)+ set
(1) t(0, 1/2, 1/2) | (2) 2 0, 0, z | (3) 2 1/4, y, 1/4 | (4) 2(1/2, 0, 0) x, 1/4, 0 |
(5) 3+(1/3, 1/3, 1/3) x - 1/3, x - 1/6, x | (6) 3+ -x + 1/2, x, -x | (7) 3+ x, -x, -x | (8) 3+ -x + 1/2, -x + 1/2, x |
(9) 3-(1/3, 1/3, 1/3) x - 1/6, x + 1/6, x | (10) 3- x + 1/2, -x, -x | (11) 3-(1/3, 1/3, -1/3) -x + 1/3, -x + 1/6, x | (12) 3- -x, x, -x |
(13) 2(3/4, 3/4, 0) x, x, 1/8 | (14) 2(-1/4, 1/4, 0) x, -x + 1/2, 3/8 | (15) 4-(0, 0, 1/4) 1/4, 0, z | (16) 4+(0, 0, 3/4) 1/4, 1/2, z |
(17) 4-(3/4, 0, 0) x, 1/2, -1/4 | (18) 2(0, 1/2, 1/2) 3/8, y - 1/4, y | (19) 2 1/8, y + 3/4, -y | (20) 4+(1/4, 0, 0) x, 0, 1/4 |
(21) 4+(0, 3/4, 0) 1/2, y, -1/4 | (22) 2(1/4, 0, 1/4) x, 1/8, x | (23) 4-(0, 1/4, 0) 0, y, 3/4 | (24) 2(-1/4, 0, 1/4) -x + 1/2, 3/8, x |
For (1/2, 0, 1/2)+ set
(1) t(1/2, 0, 1/2) | (2) 2 1/4, 1/4, z | (3) 2(0, 1/2, 0) 0, y, 1/4 | (4) 2 x, 0, 0 |
(5) 3+(1/3, 1/3, 1/3) x + 1/6, x - 1/6, x | (6) 3+ -x, x, -x | (7) 3+ x + 1/2, -x, -x | (8) 3+ -x, -x + 1/2, x |
(9) 3-(1/3, 1/3, 1/3) x - 1/6, x - 1/3, x | (10) 3-(-1/3, 1/3, 1/3) x + 1/6, -x + 1/6, -x | (11) 3- -x, -x, x | (12) 3- -x, x + 1/2, -x |
(13) 2(1/4, 1/4, 0) x, x, 1/8 | (14) 2(1/4, -1/4, 0) x, -x + 1/2, 3/8 | (15) 4-(0, 0, 1/4) 3/4, 0, z | (16) 4+(0, 0, 3/4) -1/4, 1/2, z |
(17) 4-(1/4, 0, 0) x, 1/4, 0 | (18) 2(0, 3/4, 3/4) 1/8, y, y | (19) 2(0, -1/4, 1/4) 3/8, y + 1/2, -y | (20) 4+(3/4, 0, 0) x, 1/4, 1/2 |
(21) 4+(0, 1/4, 0) 1/4, y, 0 | (22) 2(1/2, 0, 1/2) x + 1/4, 3/8, x | (23) 4-(0, 3/4, 0) -1/4, y, 1/2 | (24) 2 -x + 3/4, 1/8, x |
For (1/2, 1/2, 0)+ set
(1) t(1/2, 1/2, 0) | (2) 2(0, 0, 1/2) 1/4, 0, z | (3) 2 0, y, 0 | (4) 2 x, 1/4, 1/4 |
(5) 3+(1/3, 1/3, 1/3) x + 1/6, x + 1/3, x | (6) 3+ -x, x + 1/2, -x | (7) 3+ x + 1/2, -x - 1/2, -x | (8) 3+ -x, -x, x |
(9) 3-(1/3, 1/3, 1/3) x + 1/3, x + 1/6, x | (10) 3- x, -x, -x | (11) 3- -x + 1/2, -x + 1/2, x | (12) 3-(1/3, -1/3, 1/3) -x - 1/6, x + 1/3, -x |
(13) 2(1/2, 1/2, 0) x, x + 1/4, 3/8 | (14) 2 x, -x + 3/4, 1/8 | (15) 4-(0, 0, 3/4) 1/2, -1/4, z | (16) 4+(0, 0, 1/4) 0, 1/4, z |
(17) 4-(1/4, 0, 0) x, 3/4, 0 | (18) 2(0, 1/4, 1/4) 1/8, y, y | (19) 2(0, 1/4, -1/4) 3/8, y + 1/2, -y | (20) 4+(3/4, 0, 0) x, -1/4, 1/2 |
(21) 4+(0, 3/4, 0) 1/2, y, 1/4 | (22) 2(3/4, 0, 3/4) x, 1/8, x | (23) 4-(0, 1/4, 0) 0, y, 1/4 | (24) 2(1/4, 0, -1/4) -x + 1/2, 3/8, x |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); t(0, 1/2, 1/2); t(1/2, 0, 1/2); (2); (3); (5); (13)
Positions
Multiplicity, Wyckoff letter, Site symmetry | Coordinates | Reflection conditions | |||||||||||||||||||||||||||
(0, 0, 0)+ (0, 1/2, 1/2)+ (1/2, 0, 1/2)+ (1/2, 1/2, 0)+ | h, k, l permutable General: | ||||||||||||||||||||||||||||
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| hkl : h + k = 2n and h + l, k + l = 2n 0kl : k, l = 2n hhl : h + l = 2n h00 : h = 4n |
Special: as above, plus | |||||||||||||||||
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| no extra conditions | |||||||||||||||
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| hkl : h = 2n + 1 or h + k + l = 4n | |||||||||||||||
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| 0kl : k + l = 4n | |||||||||||||||
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| hkl : h = 2n + 1 or h, k, l = 4n + 2 or h, k, l = 4n | |||||||||||||||
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| hkl : h = 2n + 1 or h + k + l = 4n | |||||||||||||||
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Symmetry of special projections
Along [001] p4mm a' = 1/2a b' = 1/2b Origin at 1/4, 0, z | Along [111] p3m1 a' = 1/6(2a - b - c) b' = 1/6(-a + 2b - c) Origin at x, x, x | Along [110] c2mm a' = 1/2(-a + b) b' = c Origin at x, x, 1/8 |
Maximal non-isomorphic subgroups
I | [2] F231 (F23, 196) | (1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12)+ | ||||||||||||||
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IIb | none |
Maximal isomorphic subgroups of lowest index
IIc | [27] F4132 (a' = 3a, b' = 3b, c' = 3c) (210) |
Minimal non-isomorphic supergroups
I | [2] Fd-3m (227); [2] Fd-3c (228) |
II | [2] P4232 (a' = 1/2a, b' = 1/2b, c' = 1/2c) (208) |