Symmetry Operation 0 K# F9 s% i( {0 r2 Z
Symmetry operations include the Improper Rotation, Inversion Operation, Mirror Plane, and Rotation. Together, these operations create 32 crystal classes corresponding to the 32 Point Groups. & a; i- {3 c5 F+ S# P5 f1 I
The Inversion Operation takes - ^: O b3 e( j2 a" L) W1 v# f4 b(x,y,z)=>(-x,-y,-z), [' k" }1 W/ h
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. , r T5 Z* r& a( LThe Mirror Plane symmetry operation takes 0 N+ C8 K' o+ r9 t' O" x
(x,y,z)=>(x,y,-z)=>(x,-y,z) 0 K$ b f% y. wetc., which is equivalent to 2.