MIN12FAL_03_Internal Symmetry_Space Groups_Handout

Screw rotation positions of the of the motifs on the

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Unformatted text preview: e of the page. Glide Reflection Glide Glide Reflection The Glide Plane: A combined reflection and translation repeat Step 2: translate Step 1: reflect (a temporary position) Glide Reflection x x+½ in the direction of the translational component of the component of the glide reflection. Glide Reflection Glide Glide Reflection Glide Reflection Klein & Hurlbut (1993) Figure 3.24 Klein & Hurlbut (1993) Figure 3.24 Klein & Hurlbut (1993) Table 3.3 b axial glide b/2 c axial glide c/2 Diagonal glide b/2 + c/2 (100) glide plane Diamond glide b/4 + c/4 Klein & Hurlbut (1993) Figure 3.25 Graphic symbols for mirror and glide planes Graphic symbols for symmetry axes simple space groups Bloss (1971) Table 7-1 Bloss (1971) Table 7-2 Bloss (1971) Table 7-3 shortened notations o n nan Bloss (1971) Table 7-4 shortened notations o n nan shortened notations Bloss (1971) Figure 7-10 P primitive lattice P 21/b 21/a 2/m point-group symmetry symmetry 2/m 2/m 2/m orthorhombic a Bloss (1971) Figure 7-12 b c Bloss (1971) Figure 7-10 ,+ + ,, + ,, ,+ P primitive lattice point-group symmetry symmetry 2/m 2/m 2/m orthorhombic P 21/b 21/a 2/m 2/ a b c P 21/b 21/a 2/m a b c Symmetrical operation and its projection onto a plane z z z z+½ Orthorhombic I body centered lattice centered lattice Orthorhombic C C centered lattice centered lattice Identification of symmetry (repeat patterns of atoms or ions) in space lattices Projected repeat pattern of general positions Projected distribution of symmetry elements The International Tables for X-ray Crystallography Motifs (atoms Motifs (atoms, ions, or molecules) generated by glide in a unit cell projected on a specific plane. Operations of screw rotation and glide reflection Glide planes and screw axes, unlike point symmetry elements, do not reduce the multiplicity of a position which lines on them. International International Tables for X-ray Crystallography Xatomic coordinates – fractional c...
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This document was uploaded on 03/25/2014.

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