This is a Fortran77 program which implements the IUCr Validation procedures outlined in the web-document at: http://www.iucr.ac.uk/iucr-top/cif/.checking/validlist.html These are part of the automatic checks currently applied when papers are submitted to Acta Cryst C. Other journals are less stringent in their requirements, but it is very useful to run this procedure as a check on the quality of the structure determination, and as a way of spotting any potential problems. IUCRVAL is available as the source code and as precompiled executables for Windows 95/98/NT/ME/2000/XP and several Unix systems. The program should compile without problems on other operating systems - see the header in the source file iucrval.f It uses the CIFtbx2 routines of Syd Hall & Herbert Bernstein; these are also supplied with the release. There are two other files, CIF_CORE.DIC the current small molecule CIF dictionary, for checking data name validity, and SGINFO.DAT for checking space group syntax. The current version of IUCRVAL assumes both these files are present in the working directory, unless the environment variable IUCRDIR is set to the location of these files e.g. set IUCRDIR=c:\iucrval\bin\ (for DOS/Windows) Version 2 incorporates a new space group symbol interpretor, since the previous routine occasionally gave errors with some non-standard settings. Some minor modifications and bug-fixes are implemented in version 2a. Users are free to modify the program to suit local requirements. The syntax for using the program is: iucrval -v cif_name or iucrval cif_name The -v flag is optional for data name checking against CIF_CORE.DIC cif_name is the name of the CIF, where the extension .cif is assumed Installation notes (1) UNIX users Compilation information is given in the header to the source file iucrval.f (See also the important notes at the end of that file) (2) VAX-VMS and Alpha OpenVMS users The com file VMS.COM can be used to compile for VAX-VMS systems (thanks to Professor F. NICOLO - Messina ITALY). Some minor modification of CIFTBX.F may be necessary (in routine ciftbx_init) Any problems, please email me at: louis@chem.gla.ac.uk Dr Louis J. Farrugia, Dept. of Chemistry, University of Glasgow, GLASGOW G12 8QQ Scotland Phone (0)141 330 5137 FAX (0)141 330 4888