Symmetry Operation 8 n# V" _! Y8 E$ ESymmetry operations include the Improper Rotation, Inversion Operation, Mirror Plane, and Rotation. Together, these operations create 32 crystal classes corresponding to the 32 Point Groups. 0 c* X8 O1 P1 x* w8 j* R$ xThe Inversion Operation takes ) w" Q. M8 t/ o
(x,y,z)=>(-x,-y,-z) $ P# F7 Z* x: e* O- c: @ 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. , ?$ W- f! a) S2 M
The Mirror Plane symmetry operation takes , u! a1 L B) U& a( @ G( Q(x,y,z)=>(x,y,-z)=>(x,-y,z)0 b( L. i- u1 B5 A. `
etc., which is equivalent to 2.