Symmetry Operation ) G' J4 R# }6 S
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. ; b8 O5 t5 r% G* ]" m+ `The Inversion Operation takes 1 a: B# i% Z4 p4 X
(x,y,z)=>(-x,-y,-z)6 e- _: T% ?2 i. ]
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. & x0 {& E. \1 x" x6 I; M: ^; r w
The Mirror Plane symmetry operation takes 7 A: {6 E: {4 d, K# I
(x,y,z)=>(x,y,-z)=>(x,-y,z)4 Q4 ~2 ?8 D6 }1 s% ~
etc., which is equivalent to 2.