Table 25.

Reduction from 2 to 1

Space group of unstrained crystal, order 2 per lattice point		No specialization of stress		Space group of strained crystal, order 1 per lattice point
		Coordinates referred to axes of unstrained crystal (2∥Y)
No.	Symbol	1st Subset	2d Subset	No.	Symbol
3	P2	(x, y, z)	( $\overline{x}$, y, $\overline{z}$ )	1	P1
4	P21	(x, y, z)	( $\overline{x}$x,½+ y, $\overline{z}$ )	1	P1
5	C2	(x, y, z)	( $\overline{x}$, y, $\overline{z}$ )	1	P1