Graduate student Long Yang, in collaboration with Dr. Pavol Juhas (Brookhaven National Laboratory), Dr. Maxwell Terban (Max Planck Institute for Solid State Research), and Dr. Matthew Tucker (Oak Ridge National Laboratory) recently had a paper accepted in the journal Acta Crystallographica Section A that establishes a new data-mining methodology on finding candidate structures from structural databases given a measured pair distribution function (PDF) data. (https://doi.org/10.1107/S2053273320002028)

Studying advanced materials is critical to the development of science and technology. Understanding the material structure plays a key role for investigating the material properties. Structure solution of well ordered crystals is largely a solved problem, but for real materials, which may be defective or nanostructured, determining structure can be a major challenge that could itself benefit from a data-mining style approach.

Here we developed an approach we call structure-mining, to automate and manage structure model selection and PDF refinement. Using databases and heuristics for automation it has the potential to save experimenters a large amount of time as they explore candidate structures from the literature. The approach can rapidly screen large numbers of structures in a manner that is well matched to the kinds of high-throughput experiments being envisaged in the materials genomics arena.

Tests on various material systems show the effectiveness and robustness of the algorithm in finding the correct atomic crystal structure. It works on crystalline and nanocrystalline materials including complex oxide nanoparticles and nanowires, low-symmetry and locally distorted structures, and complicated doped and magnetic materials.

This approach, published in Acta Crystallographica Section A, could greatly speed up and extend the traditional structure searching workflow and enable the possibility of highly automated and high- throughput real-time PDF analysis experiments in the future.

Work in the Billinge group was funded by the US National Science Foundation (NSF) through grant DMREF-1534910. Long Yang was supported by the ORNL Graduate Opportunity (GO) program. The x-ray PDF measurements were conducted on the XPD beamline of the National Synchrotron Light Source II at Brookhaven National Laboratory. The neutron PDF measurements were carried out on the NOMAD beamline of the Spallation Neutron Source at Oak Ridge National Laboratory and the NPDF beamline at LANSCE at Los Alamos National Laboratory