Estructura de Sólidos Tema-1: Conceptos básicos de cristalografía

1. Estructura de Sólidos Tema-1: Conceptos básicos de cristalografía Conferencia 5. Tablas Internacionales Cristalográficas, simetría de los grupos espaciales.

3. TABLE I. Details on XRD data acquisition and processing. TABLE II. Atomic positions and occupation (Occ) factors for the refined crystal structure Cd[Fe(CN)5NO].

6. Crystal System Short International Symbol Schoenflies Symbol Point Group Symbol

7. Full International Hermann- Maugin Symbol Patterson symmetry: Se deriva a partir de la simetría de los grupos espaciales reemplazando ejes de tornillo y planos deslizantes con los correspondientes elementos de simetría finitos Sequential number

8. Space Groups Symmetry Diagrams Projection direction, orientation of the axes and selection of the origin of the coordinates are dependent on crystal system

9. Origin of the unit cell. Z axis arbitrarily chosen, hence there are no symmetry elements with a fixed z – coordinates in SG Cmm2 For each point with coordinate x, y, z in the general position. For non primitive SG, symmetry operation are divided in into sets. Specify the minimum set of symmetry operation, including translations that are needed to generate the SG

10. Coordinates of atoms within the unit cell + reflection conditions. • …24,…., 8, 4, 2 : site multiplicity • …f, e, …..b a : Wyckoff letters • 1, m.., .m.,…..mm2: site symmetry • Example: 4 em.. 0, y, z 0, -y, z • Atom 1: x = 0, y = 0.15, z = 0.31 • Symmetrically equivalents atoms: • Atom2: 0, -y, z + (0, 0, 0) = 0, 0.85, 0.31 • Atom3: 0, y, z + (½, ½ , 0) = 0.5, 0.65, 0.31 • Atom4: 0, -y, z + (½, ½ , 0) = 0.5, 0.65, 0.31

11. Subgrupos

12. TABLE I. Details on XRD data acquisition and processing. TABLE II. Atomic positions and occupation (Occ) factors for the refined crystal structure Cd[Fe(CN)5NO].

14. Cd(4); Fe(4); C(20); N(24); O(4): Cd[Fe(CN)5NO]; Z=4