the PDF-4/Full File and PDF-4/Organics Databases:

New Data Mining Tools for Structural Crystallography and Materials Characterisation

Brian O’Connor,^a Camden Hubbard,^b Tim Fawcett,^c and John Faber^c

^aMaterials Research Greoup, Department of Applied Physics, Curtin University of Technology, GPO Box U1987, Perth, WA 6845, Australia; ^bOak Ridge National Laboratory, Oak Ridge, TN 37831-6064, USA; ^cInternational Centre for Diffraction Data, 12 Campus Boulevard, Newtown Square, PA 18073-3273, USA (B.O'Connor@curtin.edu.au)

The ICDD is a not-for-profit organisation comprising 340 of the world’s leading x-ray scientists. It is dedicated to collecting, editing, publishing and distributing powder diffraction data for the characterisation of crystalline materials. The membership of the ICDD consists of worldwide representation from academe, government and industry. It is our mission to continue as the world centre for quality x-ray powder diffraction data to meet the needs of the technical community.

Through the combined efforts of the members and its staff of 40 at ICDD Headquarters, the organisation serves the crystallography and materials science communities (i) by producing the ICDD Powder Diffraction File (PDF) and other data base products for materials characterisation; (ii) through x-ray analysis education programs and conference management (including the Denver X-ray Conference); and (iii) through philanthropic initiatives such as scholarship support for postgraduate students working in the field.

The ICDD has recently released the PDF-4/Full File powder diffraction database which gives powder diffractionists a very sophisticated tool for data mining. PDF-4 contains over 87,000 measured patterns and approximately 49,000 patterns simulated from crystal structure data. Searches may be conducted for metals & alloys, pharmaceuticals, zeolites, superconductors, detergents pigments, ceramics, corrosion products, polymers, cement materials, forensics and explosives sub-files. Common query fields for data mining include elemental composition, formula, common name, colour, melting point, space group, unit cell dimensions, Pearson symbol, mineral classification and statistical quality of the pattern. Algorithms are provided to transform single cystal structural data into powder patterns using ‘on-the-fly’ calculations which include adjustable experimental effects such as slit configuration and crystallite broadening.

The organisation has recently released PDF-4/Organics which contains data for over 146,000 organic and organometallic phases of which almost 123,000 patterns are calculated from ICDD and CCDC single-crystal structural data. This exciting new tool has awesome data mining capability through searching 30+ separate diffraction fields and physical properties which include formula, chemical name, functional group index, drug activity, space group and unit cell dimensions. Material-type sub-files include organics, pharmaceuticals, polymers, pigments and forensics.

Examples to be described will include:

1. Making use of isomorphous phase information in the data base for structure solution

2. Pharmaceutical polymorph characterisation

3. Unknown identification