Symmetry Operation 5 o; i& _+ X: PSymmetry operations include the Improper Rotation, Inversion Operation, Mirror Plane, and Rotation. Together, these operations create 32 crystal classes corresponding to the 32 Point Groups. + ?) i! k2 t9 k
The Inversion Operation takes % L* z7 [; b7 o/ g* }- ^" A/ _4 G7 B5 w, X
(x,y,z)=>(-x,-y,-z) 8 w& ]+ p5 l5 M# P V7 I! S- g 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. ! K3 P, Q, h% F( a$ Y+ B# o
The Mirror Plane symmetry operation takes ! g. Z8 W9 T% N
(x,y,z)=>(x,y,-z)=>(x,-y,z) ; i5 O# L0 m' p5 T4 betc., which is equivalent to 2.