ICDD and FIZ sign agreement

The International Centre for Diffraction Data (ICDD) and Fachinformationszentrum,Karlsruhe, Germany, (FIZ), have signed an agreement based upon which ICDD will release a significantly enhanced powder diffraction database in September 1998. The first enhancement is the cross-correlation of the Powder Diffraction File (PDF) and the Organic Crystal Structure Database (ICSD). The automated ability to access the atomic coordinations and generate calculated patterns for potential phases identified in an unknown mixture opens a new era in phase ID. Least squares refinement of the calculated patterns will allow users to test and resolve postulates concerning preferred orientations and solid solutions to identify phases in an unknown fully automatically and unambiguously, when the appropriate information is in both of the databases (DBs). In addition, all of the other information contained in the powder patterns can be readily extracted as part of the phase ID - i.e. semi-quantitative analysis from the calculated I/I_c values, concentration of components in identified solid solutions, degrees of preferred orientation in a specimen, the crystallite size and strain of each of the phases exhibiting line broadening, etc.

For the present, the 1998 release of the PDF will be enhanced by the addition of approximately 40,000 calculated patternsobtained from ICD. This enhancement does not require that users have an ICSD license - the calculated patterns are a permanent addition to the PDF and there will be no increase in the price of the PDF. The enhanced database will follow the same format as the previous PDF-2 database. We expect the combination database to contain: Total number of entries - 115,000, Organic compounds - 20,000, Inorganic compounds - 95,000, Total entries with I/I_c - 50,000 and Unique entries with I/I_c - 37,000. Space requirements for the data files and ICDD index files will require approximately 580 MB of space. We anticipate thar this product will be distributed, inthe short term , using conventional CD-ROM technology. However, we will rapidly approach the maximum capacity of the CD-ROM. Consequently, we will be exploring the feasibility of alternative distribution media, particularly DVD technology.

ICDD, 12 Campus Blvd., Newtown Square, PA 19073-3273; FAX: 610 325-9823; WWW: www.icdd.com.