In Response to David Bradley's request, here are some helpful web sites: Intl. Union of Crystallography: http://www.iucr.ac.uk/welcome.html British Crystallographic Assocn.: http://www.cryst.bbk.ac.uk/BCA/index.html Crystallography World Wide: http://www.unige.ch/crystal/w3vlc/crystal.index.html (a pointer to almost all Xtallog resources, including software UCL Crystallography Page: http://www.ucl.ac.uk/chem/resources/crystal/index.htm Cambridge Xtallog database: http://www.ccdc.cam.ac.uk/ SHELX Home page: http://linux.uni-ac.gwdg.de/SHELX/ Crystallog World wide, Cambridge database, SHELX and UCL Homepage especially all have software pointers. There is some more data on instrument manufacturers etc etc in my home page, URL below. Hope this is of some use. Jon. Dr. Jonathan W. Steed Department of Chemistry, King's College London, Strand, London WC2R 2LS, UK. Tel: +44 (0)171 873 2117, Fax: +44 (0)171 873 2810 e-mail: jon.steed@kcl.ac.uk Web site: HTTP://CRAC3.CH.KCL.AC.UK/KCLCHEM/SUPRAMOL.HTM chemweb: A list for Chemical Applications of the Internet. Archived as: http://www.lists.ic.ac.uk/hypermail/chemweb/ To unsubscribe, send to majordomo@ic.ac.uk the following message; unsubscribe chemweb List coordinator, Henry Rzepa (rzepa@ic.ac.uk)