A type of ionic crystal structure in which the anions have an expanded face-centred cubic arrangement with the cations occupying one type of tetrahedral hole. The coordination number of each type of ion is 4. Examples of compounds with the sphalerite structure are ZnS, CuCl, CdS, and InAs.

http://www.chemtube3d.com/solidstate/_blende(final).htm An interactive version of the structure