Pcc2 jpeg

International Tables for Crysiallography (2006). Vol. A, Space group 27, pp, 222-223.

Pcc 2	r^3 ^2v				mm 2			Orthorhombic
No. 27	Pcc2						Patterson symmetry Pmmm
♦......	Pc ......H	c2 *.............	•t	n	Pblb		—	—
a «...... a, T	........-i	...........	•i	e si	—	—	—	—
♦......	«*.....	..............	•i	—	—	—	—	—
n	P2aa t		1
i—		—		*0	Ob		*0	Ob
i i 2 1			i 1 1 1	bO	0*	bo		O*
			1
i i			1 1	*0	Ol*		*0	Ob
i_			J	b©	0*		1*0	0*
i	i		i
Origin on cc 2
Asymmetric unit 0 < x < j*	o<>	<5; 0<z<l
Symmetry operations
(1) 1 (2) 2 0,0, z	(3) <r	;c,0,Z	(4) c	0,y,z

4. e

(l)x,y,z (2)x,y,z    (3)x,y,z+£    (4)x,y,z+*

Oki : 1 = 2 n

hOl : l=2n 001 : l=2n

Reflection conditions General:

CONTINUED

No. 27

Pcc 2

Generators selected (1); /(1,0,0); *(0,1,0); *(0,0,1); (2); (3) Positions

Multiplicity,    Coordinates

Wyckoff letter,

Site symmetry

Special: as above, plus

2 cl	..2 j, j,z iłśiZ+i		hkl :	l — 2n
2 c	..2 5,0,Z 5,0,Z+ 5		hkl :	1=2 n
2 b	..2 0,5, Z 0,5,Z+5		hkl :	l = 2n
2 a	..2 0,0, z 0,0,z-H		hkl :	l=2n
Symmetry of special projections Along [001] p2mm a' = a b' = b Origin at0,0,z		Along [100] p 1 m 1 a' = b b' = 5C Origin at x,0,0	Along [010] p\\m a' = |c b^! = a Origin at0,y,0

Maximal non-isomorphic subgroups

I [2]Plcl(Pc,7)    1; 3

[2]Pcl 1 (Pc, 7)    1; 4

[2] P112 (P2,3)    1; 2

Ha nonę

Hb [2] Pcn2 (a' = 2a) (Pnc2,30); [2] Pncl (b' = 2b) (30); [2] Ccc2 (a' = 2a,b' = 2b) (37)

Maximal isomorphic subgroups of lowest index

He [2] Pcc2 (a' = 2a or b' = 2b) (27); [3] Pc c2 (c^- = 3c) (27)

Minimal non-isomorphic supergroups

I    [2] Pccm (49); [2] Pcca (54); [2] Pccn (56); [2] P4₂cm(10ł); [2] P4cc (103); [2]P4c2(116)

n    [2] Ccc2(37); [2] Aem2(39); [2] Bme2(Aem2, 39); [2] lba2(45); [2]Pmm2(t - ±c)(25)