Origin at -1 on n at 1/4, 1/4, 0 from 4

Asymmetric unit

-1/4 ≤ x ≤ 1/4; -1/4 ≤ y ≤ 1/4; 0 ≤ z

(1)  1	(2)  2   1/4, 1/4, z	(3)  4+   1/4, 1/4, z	(4)  4-   1/4, 1/4, z
(5)  -1   0, 0, 0	(6)  n(1/2, 1/2, 0)   x, y, 0	(7)  -4+   1/4,-1/4, z; 1/4,-1/4, 0	(8)  -4-   -1/4, 1/4, z; -1/4, 1/4, 0

Generators selected (1); t(1, 0, 0); t(0, 1, 0); (2); (3); (5)

Positions

Multiplicity, Wyckoff letter, Site symmetry	Coordinates	Reflection conditions
		General:
8 e 1	(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, -y, -z (6) x + 1/2, y + 1/2, -z (7) y + 1/2, -x, -z (8) -y, x + 1/2, -z	hk: h + k = 2n h0: h = 2n 0k: k = 2n

		Special: as above, plus
4 d  2 . .	1/4, 3/4, z 3/4, 1/4, z 3/4, 1/4, -z 1/4, 3/4, -z	no extra conditions
4 c  -1	0, 0, 0 1/2, 1/2, 0 1/2, 0, 0 0, 1/2, 0	hk: h, k = 2n
2 b  4 . .	1/4, 1/4, z 3/4, 3/4, -z	no extra conditions
2 a  -4 . .	1/4, 3/4, 0 3/4, 1/4, 0	no extra conditions

Symmetry of special projections

Along [001]   p4 a' = 1/2(a - b)   b' = 1/2(a + b)    Origin at 1/4, 1/4, z

Along [100]   2mg a' = b    Origin at x, 0, 0

Along [110]   2mm a' = 1/2(-a + b)    Origin at x, x, 0

Maximal non-isotypic subgroups

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I	[2] p-4 (50)	1; 2; 7; 8
	[2] p4 (49)	1; 2; 3; 4
	[2] p2/n11 (p112/a, 7)	1; 2; 5; 6

IIa

none

IIb

none

Maximal isotypic subgroups of lowest index

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IIc	[5] p4/n (a' = a + 2b, b' = -2a + b or a' = a - 2b, b' = 2a + b) (52)

Minimal non-isotypic supergroups

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I	[2] p4/nbm (62); [2] p4/nmm (64)

II	[2] c4/m (p4/m, 51)

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