References Space Groups for Solid State Scientists , G. Burns and A.M.Glazer

# References Space Groups for Solid State Scientists , G. Burns and A.M.Glazer

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## References Space Groups for Solid State Scientists , G. Burns and A.M.Glazer

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1. Physics 590 “International Tables of Crystallography” “Everything you wanted to know about beautiful flies, but were afraid to ask.” Schönflies Gordie Miller (321 Spedding) • Proposed Plan • What basic information is found on the space grouppages… • Stoichiometry of the unit cell (Wyckoff sites) • Site (point) symmetry of atoms in solids • Solid-solid phase transitions (group-subgroup relationships) • Diffraction conditions – what to expect in a XRD powder pattern. References Space Groups for Solid State Scientists, G. Burns and A.M.Glazer (Little mathematical formalism; prose style) International Tables for Crystallography (http://it.iucr.org/) Bilbao Crystallographic Server (www.cryst.ehu.es) (Comprehensive resources for all space groups)

2. What can we learn from the International Tables? BaFe2As2 Space Group: I4/mmm Lattice Constants:a = 3.9630 Å c = 13.0462 Å Asymmetric Unit: Ba (2a): 0 0 0 Fe (4d): ½ 0 ¼ As (4e): 0 0 0.3544 c Intensity (Arb. Units) (hkl) Indices h + k + l= even integer (2n) (013) (116) (200) (112) (213) b a (015) (004) (028) (215) (011) (002) 2θ (Cu Kα)

3. Typical Space Group Pages… Symbolism Diffraction Extinction Conditions Point Symmetry Features Stoichiometry Structure of Unit Cell Subgroup/Supergroup Relationships

4. Symbolism Point Group of the Space Group Crystal System Space Group Molecules Solids D C B A A A B B C D D C D C ccw σh C4 B A