Cambridge Crystal Structures Database (CSD)

http://www.ccdc.cam.ac.uk/products/csd/

Inorganic (Karlsruhe) ICSD database

http://www.fiz-karlsruhe.de/icsd_content.html

http://icsdweb.fiz-karlsruhe.de

http://icsd.ill.fr/icsd/index.html

Pearson Database

http://crystalimpact.com/pcd/Default.htm

NRL-chrystalographic database

http://crystalimpact.com/pcd/Default.htm

UCSD portal

http://www.ucsd.edu/portal/site/Libraries/menuitem.346352c02aac0c82b9ba4310d34b01ca/?vgnextoid=a2d228e2fcc44110VgnVCM10000045b410acRCRD

Rutgers Scientific Scholar

http://www.libraries.rutgers.edu/rul/indexes/search_guides/scifinder.shtml#guide

CRYSTMET database : intermetallic compounds

http://www.tothcanada.com/databases.htm