Symmetry Operation 2 J- n: u% z T: n# v: o
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. ' n5 G6 D3 a: P G! [8 M( Q1 N
The Inversion Operation takes ; u; f) b' ^7 {0 I M
(x,y,z)=>(-x,-y,-z) f5 p) _# M! L+ R& ]' 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. % l7 V1 |, Z, _7 V7 ^
The Mirror Plane symmetry operation takes 8 X, F- F/ p3 P' e) p! Y" g6 f \(x,y,z)=>(x,y,-z)=>(x,-y,z)! ]4 O; |9 T( v# ~
etc., which is equivalent to 2.