Influence of Chemical and Spatial Constraints on the Structures of Inorganic Compounds

The restrictions imposed by both chemistry and three-dimensional space on the structures of inorganic crystals can be analysed using the bond-valence model and space-group theory. The bond-valence model is used to construct a bond graph (connectivity table) from which the multiplicities and possible site symmetries of each atom can be assigned. These are matched to Wyckoff positions of the three-dimensional space groups, selecting the matching space group with the highest possible symmetry. High-symmetry structures such as NaCl, perovskite and garnet are readily derived from the chemical formula and, with a little more effort, the same can be done for structures of intermediate symmetry such as wurtzite, corundum and rutile. For other compounds a relationship between the site symmetry and the multiplicity of an atom can severely restrict the possible structures.

Influence of Chemical and Spatial Constraints on the Structures of Inorganic Compounds Journal Articles