CONTINUED No. 204 Im
¯
3
Generators selected (1); t(1, 0,0); t(0,1,0); t(0,0,1); t(
1
2
,
1
2
,
1
2
); (2); (3); (5); (13)
Positions
Multiplicity,
Wyckoff letter,
Site symmetry
Coordinates
(0,0, 0)+ (
1
2
,
1
2
,
1
2
)+
Reflection conditions
h,k,l cyclically permutable
General:
48 h 1(1)x,y, z (2) ¯x, ¯y,z (3) ¯x,y, ¯z (4) x, ¯y, ¯z
(5) z,x,y (6) z, ¯x, ¯y (7) ¯z, ¯x,y (8) ¯z,x, ¯y
(9) y,z,x (10) ¯y,z, ¯x (11) y, ¯z, ¯x (12) ¯y, ¯z,x
(13) ¯x, ¯y
, ¯z (14) x,y, ¯z (15) x, ¯y,z (16) ¯x,y, z
(17) ¯z, ¯x, ¯y (18) ¯z, x,y (19) z,x, ¯y (20) z, ¯x,y
(21) ¯y, ¯z, ¯x (22) y, ¯z,x (23) ¯y,z,x (24) y,z, ¯x
hkl : h + k + l = 2n
0kl : k + l = 2 n
hhl : l
= 2n
h00 : h = 2n
Special: as above, plus
24 gm.. 0, y,z 0, ¯y,z 0,y, ¯z 0, ¯y, ¯zz,0, yz,0, ¯y
¯z,0,y ¯z,0, ¯yy,z,0¯y , z,0 y, ¯z,0¯y, ¯z,0
no extra conditions
16 f . 3 . x,x,x ¯x, ¯x,x ¯x,
x, ¯xx, ¯x, ¯x
¯x, ¯x, ¯xx,x, ¯xx, ¯x,x ¯x,x, x
no extra conditions
12 emm2.. x,0,
1
2
¯x,0,
1
2
1
2
,x,0
1
2
, ¯x, 00,
1
2
,x 0,
1
2
, ¯x no extra conditions
12 dmm2.. x,0 , 0¯x,0,00,x,00, ¯x,00,0,x 0,0, ¯x no extra conditions
8 c .
¯
3 .
1
4
,
1
4
,
1
4
3
4
,
3
4
,
1
4
3
4
,
1
4
,
3
4
1
4
,
3
4
,
3
4
hkl : k,l = 2n
6 bmmm.. 0,
1
2
,
1
2
1
2
,0,
1
2
1
2
,
1
2
,0 no extra conditions
2 am
¯
3 . 0,0,0 no extra conditions
Symmetry of special projections
Along [001] c2mm
a
= ab
= b
Origin at 0,0,z
Along [111] p6
a
=
1
3
(2a − b− c) b
=
1
3
(−a + 2b − c)
Origin at x,x , x
Along [110] p2mm
a
=
1
2
(−a + b) b
=
1
2
c
Origin at x,x , 0
Maximal non-isomorphic subgroups
I
[2] I 23 (197) (1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12)+
[3] Im1(Immm, 71) (1; 2; 3; 4; 13; 14; 15; 16)+
⎧
⎪
⎪
⎨
⎪
⎪
⎩
[4] I 1
¯
3(R
¯
3, 148) (1; 5; 9; 13; 17; 21)+
[4] I 1
¯
3(R
¯
3, 148) (1; 6; 12; 13; 18; 24)+
[4] I 1
¯
3(R
¯
3, 148) (1; 7; 10; 13; 19; 22)+
[4] I 1
¯
3(R
¯
3, 148) (1; 8; 11; 13; 20; 23)+
IIa [2] Pn
¯
3 (201) 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; (13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24)+(
1
2
,
1
2
,
1
2
)
[2] Pm
¯
3 (200) 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24
IIb none
Maximal isomorphic subgroups of lowest index
IIc
[27] Im
¯
3(a
= 3a,b
= 3b,c
= 3c) (204)
Minimal non-isomorphic supergroups
I
[2] Im
¯
3m (229)
II [4] Pm
¯
3(a
=
1
2
a,b
=
1
2
b,c
=
1
2
c) (200)
629