Inorganic chemistry crystal lattice

The range of inorganic chemistry includes both molecular compounds, which exist as discrete molecules, and crystals, whose structures are described by infinite lattices of regularly-ordered atoms and which are studied by crystallography and solid-state chemistry. Sec also Solid-State Chemistry. 

Inorganic Chemistry From the discrete lattice of crystal symmetry to the continuous manifolds of differential geometry... 

Contrary to the impressions conveyed by most textbooks of structural inorganic chemistry and many of the standard works on X-ray crystallography, the architecture of solids is seldom faultless. These texts often imply that all crystals are made up of a large number of properly packed and regularly stacked unit cells, without suggestion of imperfection. Yet, if it were not for the presence of lattice defects, it would be extremely difficult to account for a wide range of phenomena, including... 

Therefore in inorganic supramolecular chemistry there is a new meaning for the term crystal field (originally developed for metal ions doped in crystal lattices). The supramolecular crystal field is the total influence of the crystal surroundings on a target molecule the magnitude, symmetry and anisotropy of the crystal field are important. We must continually ask to what extent the structures of molecular inorganic compounds are different in solution phases and crystal lattices, and seek quantification of this crystal field and its influences. 

Hellner, E. (1965). Descriptive Symbols for Crystal-Structure Types and Homeotypes Based on Lattice Complexes. Acta Ciyst. 19,703 - 712. lUPAC (1990). "Nomenclature of Inorganic Chemistry". Oxford Blackwell. 

Hoppe, R., 1975, The Madelung part of the lattice energy, MAPLE, as a guide in crystal chemistry, irt Crystal Stnrctirre and Chemical Bonding in Inorganic Chemistry, eds C.J.M. Rooymarrs and A. Rabenau (North-Holland, Amsterdam) pp. 127-161. 

Note the ground-state atomic term symbol for Cr is F, which splits into T2, Ti and A2 for an octahedral transition metal complex. For more information regarding term symbol notation and absorption spectra for transition metal complexes, see Shiiver et al. Inorganic Chemistry, 4th ed., W. H. Freeman New York, 2006. http //www.scribd.com/doc/6672586/Electronic-Spectroscopy-l Note excited electrons give off their energy via infrared emission and thermal interactions with the corundum crystal lattice, referred to as electron-phonon (lattice vibrations) interactions. 

Let us turn the spotlight on a example from inorganic chemistry a ZnO crystal. For simplicity we will suppose that the crystal is built up by Zn++- and O -ions. Semiconduction is negligible at low temperature. Thermal agitation or absorption of light quanta kicks out an electron producing two radicals °Zn+ and °0-. They will run through the crystal lattice ... 

International Centre for Diffraction Data - Maintains and distributes the Powder Diffraction File (PDF), a file of x-ray powder diffraction patterns used for identification of crystalline materials. The ICDD also distributes the NIST Crystal Data file, which contains lattice parameters for over 235,000 inorganic and organic crystalline materials. Address 12 Campus Blvd., Newton Square, PA 19073-3273 [icdd.com]. Research Collaboratory for Structoral Bioinformatics - Maintains the Protein Data Bank (PDB), a file of 3-dimensional structures of proteins and other biological macromolecules. Address Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854-8087 [www.rcsb.org]. 

---