Pma2 jpeg

International Tables for Crystallography (2006). Voł. A, Space group 28, pp. 224-225.

Pma 2    Ct

mm 2    Orthorhombic

No. 28

Pma 2

Patterson symmetry Pmmm

Pma2

♦— 1	—♦— i	—♦
1 i ^£ ?	i ♦ i	1 ♦ i
1 ♦—	1 —♦—	I —t
n	PI cm f	f
£ j : : i i i i
i	1	I

r

*o		*o
	o*
	o*
-o		*0
♦o		*o

o    o*

Origin on lo2

Asymmetric unit 0 <* < J; 0 < y < 1; 0 < z < 1 Symmetry operations

(1) 1    (2) 2 0,0,z    (3) a x,0,z    (4) m ),y,z

CONTINUED

No. 28

Pma 2

Generators selected (1); f(l,0,0); /(0,1-0); /(0,0,1); (2); (3) Positions

Multiplicity,    Coordinates

Wyckoff letter,

Site symmetry

Reflection conditions General:

4	d 1	(D*,y,z	(2) x,y,z	(3) \,y,z	(4)x+j,y,z	hOl : h = 2n A00: h = 2n
						Special: as above, plus
2	c m..		19,*			no extra conditions
2	b ..2	0,i ,z	5,Z			hkl : h = 2n
2	a ..2	0,0, Z	j,0, Z			hkl : h = 2n

Along [001] plmg a = a b = b

Origin at 0,0, z

Along [100] p Im 1 a' = b b' = c Origin at x, 0,0

Along jOlO] pllm a' = c b' = |a Origin at0,y,0

Symmetry of special projections

Maximal non-isomorphic subgroups

I [2] Pio 1 (Pc, 7)    1; 3

[2j Pm 11 (Pm, 6)    1; 4

[2]PI 12(P2,3)    1; 2

Ila nonę

Ilb [2] Pba2(b' = 2b) (32); [2] Pmn2, (c = 2c) (31); [2] Pcn2 (c¹ = 2c) (Pnc2,30); [2]Pca2, (c* = 2c) (29); [2) Aea2(b' = 2b,ć = 2c) (41); [2]Ama2 (b' = 2b,c' = 2c) (40)

Maximal isomorphic subgroups of lowest index

Dc [2] Pma 2 (b' = 2b) (28); [2] Pm a 2 (ć = 2c) (28); [3] Pma2 (a' = 3a) (28)

Minimal non-isomorphic supergroups

I    [2]Pccm(49); [2JPmma(51); [2]Pmna(53); [2]Pbcm(57)

II    [2] Cmm2 (35); [2] Bme2 (Aem2, 39); [2] Ama2 (40); [2] lma2 (46); [2] Pmm2 (a' = ?a)(25)

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