Origin at -1 on glide plane a

Asymmetric unit

0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1/2; 0 ≤ z

(1)  1

(2)  2   1/4, 0, z

(3)  -1   0, 0, 0

(4)  a   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 e 1	(1) x, y, z (2) -x + 1/2, -y, z (3) -x, -y, -z (4) x + 1/2, y, -z	hk: h = 2n h0: h = 2n

		Special: no extra conditions
2 d  2	1/4, 1/2, z 3/4, 1/2, -z
2 c  2	1/4, 0, z 3/4, 0, -z
2 b  -1	0, 1/2, 0 1/2, 1/2, 0
2 a  -1	0, 0, 0 1/2, 0, 0

Symmetry of special projections

Along [001]   p2 a' = 1/2a   b' = b    Origin at 0, 0, z

Along [100]   2mm a' = bp    Origin at x, 0, 0

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

Maximal non-isotypic subgroups

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I	[2] p11a (5)	1; 4
	[2] p112 (3)	1; 2
	[2] p-1 (2)	1; 3

IIa

none

IIb

none

Maximal isotypic subgroups of lowest index

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IIc	[2] p112/a (b' = 2b or a' = a + 2b, b' = 2b) (7)

Minimal non-isotypic supergroups

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I	[2] pmaa (38); [2] pban (39); [2] pmma (41); [2] pman (42); [2] pbaa (43); [2] pbma (45); [2] pmmn (46); [2] cmme (48); [2] p4/n (52)

II	[2] p112/m (a' = 1/2a) (6)

DIFFERENT CELL CHOICES

p112/a

CELL CHOICE 1

Origin at -1 on glide plane a

Asymmetric unit

0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1/2; 0 ≤ 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 e 1	(1) x, y, z (2) -x + 1/2, -y, z (3) -x, -y, -z (4) x + 1/2, y, -z	hk: h = 2n h0: h = 2n

		Special: no extra conditions
2 d  2	1/4, 1/2, z 3/4, 1/2, -z
2 c  2	1/4, 0, z 3/4, 0, -z
2 b  -1	0, 1/2, 0 1/2, 1/2, 0
2 a  -1	0, 0, 0 1/2, 0, 0

p112/n

CELL CHOICE 2

Origin at -1 on glide plane n

Asymmetric unit

0 ≤ x ≤ 1/4; 0 ≤ y ≤ 1; 0 ≤ 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 e 1	(1) x, y, z (2) -x + 1/2, -y + 1/2, z (3) -x, -y, -z (4) x + 1/2, y + 1/2, -z	hk: h + k = 2n h0: h = 2n 0k: k = 2n

		Special: no extra conditions
2 d  2	1/4, 3/4, z 3/4, 1/4, -z
2 c  2	3/4, 3/4, z 1/4, 1/4, -z
2 b  -1	1/2, 0, 0 0, 1/2, 0
2 a  -1	0, 0, 0 1/2, 1/2, 0

p112/b

CELL CHOICE 3

Origin at -1 on glide plane b

Asymmetric unit

0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1/2; 0 ≤ 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 e 1	(1) x, y, z (2) -x, -y + 1/2, z (3) -x, -y, -z (4) x, y + 1/2, -z	hk: k = 2n 0k: k = 2n

		Special: no extra conditions
2 d  2	1/2, 3/4, z 1/2, 1/4, -z
2 c  2	0, 1/4, z 0, 3/4, -z
2 b  -1	1/2, 1/2, 0 1/2, 0, 0
2 a  -1	0, 0, 0 0, 1/2, 0

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