Crystal structures

Crystal structures There are a number of sources for crystal structures. The primary literature (i.e. journal articles) contain crystal structure information and very often a figure showing the crystal structure and coordination of the atoms. Some crystal structures are available in a general web search. There are a number of databases of crystal structures, some of which are pay for access (e.g. Springer materials and ICSD). Several free sources include: Wiki Crystallography Database, ICSD for WWW, American Mineralogical Crystal Structure Database.

To find the crystal structure of CuCl2, use the Wiki Crystallography Database. Search with the following input:

Searching with these criteria, there are three results for compounds containing only copper and chlorine.

Download the CIF file for CuCl2. The cif file contains information needed to create the crystal structure. Visualization programs, such as VESTA, can be used to open the CIF file and visualize the crystal structure. The default structure building parameters show copper has a coordination number of four and adopts a square planar geometry, but noting the electron configuration of Cu2+ and the Jahn-Teller effect, there are four short (2.26 Å) and two long (2.96 Å) Cu-Cl bonds making this an elongated octahedral geometry (see Fig. 20.10 in Housecroft and Sharpe, Inorganic Chemistry, 4th).