Microscopic Symmetry Elements Symmetry Elements: moves all the poi (Space Symmetry Elements ranslation the asymmetric unit the same distance in the Pl. Lattice-its corresponding operation -same direction. This has I combination of a rotation and a translational symmetry. the plane. There are no b3. glide planes -combination of a refection Invariant points un and a translational symmetry All these action are space symmetry. Every point ged, but the space do not hange after the action. So, their symmetry is called space groups Glide reflection reflects the asymmetric Glide planes unit across a mirror line ◆ and then translates a glide plane is a combination of a reflection and axis of a glid parallel to the mirror. A reflection handedness of figures in The orientation of the plane and it the asymmetric unit. There determine what sort of translation are no invariant points prime mm R under a glide reflection b glide parallel to(001) albr did foetal Glide Reflection: A glide reflection combines a reflection with a translation along the direction of the mirror line Diagonal glide Diamond glides the diagonal glide(n-glide) have a displacement the diamond glide(d-glide) have a displacement vector of v(a+b) vector of y(a+b)11 Microscopic Symmetry Elements (Space Symmetry Elements) 1. Lattice — — its corresponding operation is translational symmetry. 2. screw axes — — combination of a rotation and a translational symmetry. 3. glide planes — — combination of a refection and a translational symmetry. All these action are space symmetry. Every point in the space is changed, but the space do not change after the action. So, their symmetry is called space groups. Symmetry Elements: Translation moves all the points in the asymmetric unit the same distance in the same direction. This has no effect on the handedness of figures in the plane. There are no invariant points under a translation. A C a r a r b r Glide Reflection reflects the asymmetric unit across a mirror line and then translates parallel to the mirror. A glide reflection changes the handedness of figures in the asymmetric unit. There are no invariant points under a glide reflection. Glide Reflection: A glide reflection combines a reflection with a translation along the direction of the mirror line. A glide plane is a combination of a reflection and a translation. The orientation of the plane and its symbol determine what sort of translation is involved. b glide parallel to (001) Glide Planes Diagonal Glide the diagonal glide (n-glide) have a displacement vector of ½(a+b). Diamond Glides the diamond glide (d-glide) have a displacement vector of ¼(a+b)