Origin on b2a

Asymmetric unit

0 ≤ x ≤ 1/4; 0 ≤ y ≤ 1; 0 ≤ z

For (0, 0, 0)+ set

(1)  1

(2)  2   0, y, 0

(3)  m   1/4, y, z

(4)  a   x, y, 0

For (1/2, 1/2, 0)+ set

(1)  t(1/2, 1/2, 0)

(2)  2(0, 1/2, 0)   1/4, y, 0

(3)  b   0, y, z

(4)  b   x, y, 0

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

Positions

Multiplicity, Wyckoff letter, Site symmetry	Coordinates	Reflection conditions
	(0, 0, 0)+  (1/2, 1/2, 0)+	General:
8 c 1	(1) x, y, z (2) -x, y, -z (3) -x + 1/2, y, z (4) x + 1/2, y, -z	hk: h, k = 2n h0: h = 2n 0k: k = 2n

		Special: no extra conditions
4 b  m . .	1/4, y, z 3/4, y, -z
4 a  . 2 .	0, y, 0 1/2, y, 0

Symmetry of special projections

Along [001]   p1m1 a' = 1/2a   b' = 1/2b    Origin at 0, 0, z

Along [100]   11m a' = 1/2b    Origin at x, 0, 0

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

Maximal non-isotypic subgroups

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I	[2] cm11 (13)	(1; 3)+
	[2] c121 (c211, 10)	(1; 2)+
	[2] c11a (p11a, 5)	(1; 4)+

IIa	[2] pb21a (33)	1; 4; (2; 3) + (1/2, 1/2, 0)
	[2] pm2a (31)	1; 2; 3; 4
	[2] pb2b (30)	1; 2; (3; 4) + (1/2, 1/2, 0)
	[2] pm21b (28)	1; 3; (2; 4) + (1/2, 1/2, 0)

IIb

none

Maximal isotypic subgroups of lowest index

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IIc	[3] cm2e (a' = 3a) (36); [3] cm2e (b' = 3b) (36)

Minimal non-isotypic supergroups

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I	[2] cmme (48)

II	[2] pm2m (a' = 1/2a, b' = 1/2b) (27)

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