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. 1965 Sep-Oct;69A(5):461–479. doi: 10.6028/jres.069A.049

Table 22.

Reduction from 222 to 2

Space group of unstrained
crystal, order 4 per lattice point
If stressed so that xX, Y, or Z Space group of strained
crystal, order 2 per lattice point
If stressed so that yX, Y, or Z Space group of strained
crystal, order 2 per lattice point
If stressed so that zX, Y, or Z Space group of strained
crystal, order 2 per lattice point
Coordinates referred to axes of unstrained crystal Coordinates referred to axes of unstrained crystal Coordinates referred to axes of unstrained crystal
No. Symbol 1st Subset 2d Subset No. Symbol 1st Subset 2d Subset No. Symbol 1st Subset 2d Subset No. Symbol
16 P222 ( x, y, z)
( x, y¯, z¯)
( x¯, y, z¯)
( x¯, y¯, z)
3 P2 ( x, y, z)
( x¯, y, z¯)
( x, y¯, z¯)
( x¯, y¯, z)
3 P2 ( x,y, z)
( x¯,y¯, z)
( x, y¯, z¯)
( x¯, y, z¯)
3 P2
17 P2221 ( x, y, z)
( x, y¯, z¯)
( x¯, y, ½- z)
( x¯, y¯, ½+ z)
3 P2 ( x, y, z)
( x¯, y, ½- z)
( x, y¯, z¯)
( x¯, y¯, ½+ z)
3 P2 ( x,y, z)
( x¯,y¯, ½+ z)
( x, y¯, z¯)
( x¯, y, ½- z)
4 P21
18 P21212 ( x, y, z) (½+x, ½-y, z¯) (½-x, ½+ y, z¯)
( x¯, y¯, z)
4 P21 ( x, y, z)
(½-x, ½+y, z¯)
(½+x, ½- y, z¯)
( x¯, y¯, z)
4 P21 ( x,y, z)
( x¯,y¯, z)
(½+x, ½- y, z¯) (½-x, ½+ y, z¯) 3 P2
19 P212121 ( x, y, z) (½+x, ½-y, z¯) ( x¯, ½+ y, ½- z)
(½-x, y¯, ½+ z)
4 P21 ( x, y, z)
( x¯, ½+y , ½- z)
(½+x, ½- y, z¯) (½-x, y¯, ½+ z) 4 P21 ( x,y, z)
(½-x,y¯, ½+z)
(½+x, ½- y, z¯)
( x¯,½+y, ½- z)
4 P21
20 C2221 ( x, y, z)
( x, y¯, z¯)
( x¯, y, ½- z)
( x¯, y¯, ½+ z)
5 C2 ( x, y, z)
( x¯, y, ½- z)
( x, y¯, z¯)
( x¯, y¯, ½+ z)
5 C2 ( x,y, z)
( x¯,y¯, ½+ z)
( x, y¯, z¯)
( x¯, y, ½- z)
4 P21
21 C222 ( x, y, z)
( x, y¯, z¯)
( x¯, y, z¯)
( x¯, y¯, z)
5 C2 ( x, y, z)
( x¯, y, z¯)
( x, y¯, z¯)
( x¯, y¯, z)
5 C2 ( x,y, z)
( x¯,y¯, z)
( x, y¯, z¯)
( x¯, y, z¯)
3 P2
22 F222 ( x, y, z)
( x, y¯, z¯)
( x¯, y, z¯)
( x¯, y¯, z)
5 C2 ( x, y, z)
( x¯, y, z¯)
( x, y¯, z¯)
( x¯, y¯, z)
5 C2 ( x,y, z)
( x¯,y¯, z)
( x, y¯, z¯)
( x¯, y, z¯)
5 C2
23 I222 ( x, y, z)
( x, y¯, z¯)
( x¯, y, z¯)
( x¯, y¯, z)
5 C2 ( x, y, z)
( x¯, y, z¯)
( x, y¯, z¯)
( x¯, y¯, z)
5 C2 ( x,y, z)
( x¯,y¯, z)
( x, y¯, z¯)
( x¯, y, z¯)
5 C2
24 I212121 ( x, y, z) (½+x, ½-y, z¯) ( x¯, ½+ y, ½- z)
(½-x, y¯, ½+ z)
5 C2 ( x, y, z)
( x¯, ½+y , ½+ z)
(½+x, ½- y, z¯) (½-x, y¯, ½+ z) 5 C2 ( x,y, z)
(½-x,y¯, ½+z)
(½+x, ½- y, z¯)
( x¯,½+y, ½- z)
5 C2