Origin on 1a2

Asymmetric unit

0 ≤ x ≤ 1/4; 0 ≤ y ≤ 1

(1)  1

(2)  2   0, 0, z

(3)  a   x, 0, z

(4)  m   1/4, y, z

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

Positions

Multiplicity, Wyckoff letter, Site symmetry	Coordinates	Reflection conditions
		General:
4 d 1	(1) x, y, z (2) -x, -y, z (3) x + 1/2, -y, z (4) -x + 1/2, y, z	h0: h = 2n

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

Symmetry of special projections

Along [001]   p2mg a' = a   b' = b    Origin at 0, 0, z

Along [100]   1m1 a' = b    Origin at x, 0, 0

Along [010]   1m1 a' = 1/2a    Origin at 0, y, 0

Maximal non-isotypic subgroups

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I	[2] p1a1 (pb11, 12)	1; 3
	[2] pm11 (11)	1; 4
	[2] p112 (3)	1; 2

IIa

none

IIb	[2] pba2 (b' = 2b) (25)

Maximal isotypic subgroups of lowest index

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IIc	[2] pma2 (b' = 2b) (24); [3] pma2 (a' = 3a) (24)

Minimal non-isotypic supergroups

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I	[2] pmaa (38); [2] pmam (40); [2] pman (42); [2] pbma (45)

II	[2] cmm2 (26); [2] pmm2 (a' = 1/2a) (23)

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