ICSD

ICSD is a database of inorganic materials operated by FIZ Karlsruhe, containing more than 260,000 crystal structures.  About 12,000 structures have been added every year. ICSD contains information on minerals, ceramics, and intermetallic compounds based on X-ray analysis, and structural data on these can be obtained in CIF format. There is a web version that can be used by logging in with an account, and a desktop version (Windows only) that can be installed locally.