Origin on 2

Asymmetric unit

0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1/2

For (0, 0, 0)+ set

(1)  1

(2)  2   x, 0, 0

For (1/2, 1/2, 0)+ set

(1)  t(1/2, 1/2, 0)

(2)  2(1/2, 0, 0)   x, 1/4, 0

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

Positions

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

		Special: no extra conditions
2 a  2	x, 0, 0

Symmetry of special projections

Along [001]   c1m1 a' = bp   b' = -a    Origin at 0, 0, z

Along [100]   211 a' = 1/2b    Origin at x, 0, 0

Along [010]   11m a' = 1/2a    Origin at 0, y, 0

Maximal non-isotypic subgroups

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I

[2] c1 (p1, 1)

1+

IIa	[2] p2111 (9)	1; 2 + (1/2, 1/2, 0)
	[2] p211 (8)	1; 2

IIb

none

Maximal isotypic subgroups of lowest index

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IIc	[3] c211 (a' = 3a) (10)

Minimal non-isotypic supergroups

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I	[2] c2/m11 (18); [2] c222 (22); [2] cm2m (35); [2] cm2e (36); [3] p312 (67); [3] p321 (68)

II	[2] p211 (a' = 1/2a, b' = 1/2b) (8)

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