Origin on 12₁a

Asymmetric unit

0 ≤ x ≤ 1/4; 0 ≤ y ≤ 1

(1)  1

(2)  2(0, 1/2, 0)   0, y, 0

(3)  a   x, y, 0

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

Symmetry of special projections

Along [001]   p1g1 a' = 1/2a   b' = b    Origin at 0, 0, z

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

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

Maximal non-isotypic subgroups

---

I	[2] pb11 (12)	1; 4
	[2] p1211 (p2111, 9)	1; 2
	[2] p11a (5)	1; 3

IIa

none

IIb

none

Maximal isotypic subgroups of lowest index

---

IIc	[3] pb21a (a' = 3a) (33); [3] pb21a (b' = 3b) (33)

Minimal non-isotypic supergroups

---

I	[2] pbaa (43); [2] pbma (45)

II	[2] cm2e (36); [2] p21am (a' = 1/2a) (pb21m, 29); [2] pm2a (b' = 1/2b) (31)

---