Symmetry Operation 0 x% M# ~% f( `3 y' c9 P- C" o$ G/ vSymmetry operations include the Improper Rotation, Inversion Operation, Mirror Plane, and Rotation. Together, these operations create 32 crystal classes corresponding to the 32 Point Groups. ( G5 I" J& M1 H) z- x* R
The Inversion Operation takes 7 G2 w% [9 A! M g; r
(x,y,z)=>(-x,-y,-z) ( G% X. f6 j/ _. }; p" a' E and is denoted i. When used in conjunction with a Rotation, it becomes an Improper Rotation. An Improper Rotation by 360/n . For periodic crystals, the Crystallography Restriction allows only the Improper Rotations 1, 2, 3, 4, and 6. / n. p& L" W7 j( e( H9 L$ TThe Mirror Plane symmetry operation takes + I4 c0 E e: t! z6 T(x,y,z)=>(x,y,-z)=>(x,-y,z)3 s ?: r4 u# A$ _6 Z
etc., which is equivalent to 2.