Table 22.
Reduction from 222 to 2
| Space group of unstrained crystal, order 4 per lattice point |
If stressed so that x ∥ X, Y, or Z | Space group of strained crystal, order 2 per lattice point |
If stressed so that y ∥ X, Y, or Z | Space group of strained crystal, order 2 per lattice point |
If stressed so that z ∥ X, 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) |
3 | P2 | ( x, y,
z) ( , y, ) |
( x, ,
) ( , , z) |
3 | P2 | ( x,y,
z) ( ,, z) |
( x, ,
) ( , y, ) |
3 | P2 |
| 17 | P2221 | ( x, y,
z) ( x, , ) |
( , y,
½-
z) ( , , ½+ z) |
3 | P2 | ( x, y,
z) ( , y, ½- z) |
( x, ,
) ( , , ½+ z) |
3 | P2 | ( x,y,
z) ( ,, ½+ z) |
( x, ,
) ( , y, ½- z) |
4 | P21 |
| 18 | P21212 | ( x, y, z) (½+x, ½-y, ) | (½-x, ½+
y, ) ( , , z) |
4 | P21 | ( x, y,
z) (½-x, ½+y, ) |
(½+x, ½-
y, ) ( , , z) |
4 | P21 | ( x,y,
z) ( ,, z) |
(½+x, ½- y, ) (½-x, ½+ y, ) | 3 | P2 |
| 19 | P212121 | ( x, y, z) (½+x, ½-y, ) | ( ,
½+ y, ½-
z) (½-x, , ½+ z) |
4 | P21 | ( x, y,
z) ( , ½+y , ½- z) |
(½+x, ½- y, ) (½-x, , ½+ z) | 4 | P21 | ( x,y,
z) (½-x,, ½+z) |
(½+x, ½-
y, ) ( ,½+y, ½- z) |
4 | P21 |
| 20 | C2221 | ( x, y,
z) ( x, , ) |
( , y,
½-
z) ( , , ½+ z) |
5 | C2 | ( x, y,
z) ( , y, ½- z) |
( x, ,
) ( , , ½+ z) |
5 | C2 | ( x,y,
z) ( ,, ½+ z) |
( x, ,
) ( , y, ½- z) |
4 | P21 |
| 21 | C222 | ( x, y,
z) ( x, , ) |
( , y,
) ( , , z) |
5 | C2 | ( x, y,
z) ( , y, ) |
( x, ,
) ( , , z) |
5 | C2 | ( x,y,
z) ( ,, z) |
( x, ,
) ( , y, ) |
3 | P2 |
| 22 | F222 | ( x, y,
z) ( x, , ) |
( , y,
) ( , , z) |
5 | C2 | ( x, y,
z) ( , y, ) |
( x, ,
) ( , , z) |
5 | C2 | ( x,y,
z) ( ,, z) |
( x, ,
) ( , y, ) |
5 | C2 |
| 23 | I222 | ( x, y,
z) ( x, , ) |
( , y,
) ( , , z) |
5 | C2 | ( x, y,
z) ( , y, ) |
( x, ,
) ( , , z) |
5 | C2 | ( x,y,
z) ( ,, z) |
( x, ,
) ( , y, ) |
5 | C2 |
| 24 | I212121 | ( x, y, z) (½+x, ½-y, ) | ( ,
½+ y, ½-
z) (½-x, , ½+ z) |
5 | C2 | ( x, y,
z) ( , ½+y , ½+ z) |
(½+x, ½- y, ) (½-x, , ½+ z) | 5 | C2 | ( x,y,
z) (½-x,, ½+z) |
(½+x, ½-
y, ) ( ,½+y, ½- z) |
5 | C2 |