Symmetry Operation ( w& K; \$ b# I2 NSymmetry 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: Q; }. K1 s
The Inversion Operation takes 9 A8 j- D C4 Y/ K0 _3 }(x,y,z)=>(-x,-y,-z) 9 d& [6 H, O0 e( G/ t 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. 9 ~4 }/ f- Q6 w# C
The Mirror Plane symmetry operation takes $ c I; t M6 q(x,y,z)=>(x,y,-z)=>(x,-y,z) , Y$ @- ^; x3 Betc., which is equivalent to 2.