THE POWDER DIFFRACTION FILE (PDF): A RELATIONAL DATABASE FOR ELECTRON DIFFRACTION

The ICDD is in the midst of an exciting transition to relational database formats for the Powder Diffraction File (PDF) [1,2]. The PDF-4+ 2005 will be released in August, 2005. This database will contain approximately ~80,000 new entries with complete atomic coordinate information. Using the coordinate and structure data, powder patterns will be calculated for electron, neutron and x-ray diffraction; these are calculated on-the-fly (as needed). In addition to the standard peak intensity listing in the PDF, integrated intensity information will be available for all unique hkls within each entry. The aim of these initiatives is to enhance our capability to perform materials design. Fully digitized powder patterns are a first step in the realization of this process (see Figure 1). Search-indexing techniques that involve Hanawalt, Fink and Long8 searches are currently available in the SIeve+ plug-in to the PDF-4 database [3]. Coupling these search functions with chemical constraints provide an extraordinarily powerful set of analysis tools as applied for example, to SEM/EDS combined with high-resolution Electro