Origin on b2₁m

Asymmetric unit

0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1; 0 ≤ z

(1)  1

(2)  2(0, 1/2, 0)   0, y, 0

(3)  b   0, y, z

(4)  m   x, y, 0

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

Positions

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

		Special: no extra conditions
2 a  . . m	x, y, 0 -x, y + 1/2, 0

Symmetry of special projections

Along [001]   p1g1 a' = a   b' = b    Origin at 0, 0, z

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

Along [010]   2mm a' = a    Origin at 0, y, 0

Maximal non-isotypic subgroups

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I	[2] pb11 (12)	1; 3
	[2] p1211 (p2111, 9)	1; 2
	[2] p11m (4)	1; 4

IIa

none

IIb	[2] pb21a (a' = 2a) (33)

Maximal isotypic subgroups of lowest index

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IIc	[2] pb21m (a' = 2a) (29); [3] pb21m (b' = 3b) (29)

Minimal non-isotypic supergroups

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I	[2] pmam (40); [2] pbam (44)

II	[2] pm2m (b' = 1/2b) (27)

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