Welcome to the DiffPy project.

This is an open-source project to develop python software modules for diffraction and the study of atomic structure of materials. DiffPy is developed as part of DANSE, a software construction project funded by the National Science Foundation to provide data analysis software tools for neutron scattering experiments that will be carried out at the Spallation Neutron Source at Oak Ridge National Laboratory.

News

• 2009-04-10 - release 1.0-r3067. Contains many improvements and bugfixes, simple installation and easy code updates.

Products

DiffPy library

A library of Python modules for carrying out structure analysis tasks from diffraction data. The modules are at different stages of development and some are not yet ready for usage by non-experts. Nevertheless, the components listed below should be stable enough and hopefully useful to a broader non-expert community.

DiffPy components

• PDFgui - a program for full-profile fitting of the atomic pair distribution function (PDF) derived from x-ray or neutron diffraction data. This is a graphical front end for the PDFfit2 refinement program, with built in graphical and structure visualization capabilities.
• PDFfit2 - the structure refinement engine for fitting structural models to experimentally derived PDFs. It is used as calculation engine for PDFgui, but can be used separately in simple Python scripts or as a command-line program.
• Structure - simple storage and manipulation of crystal structure data. Supports reading and writing in several structure formats, coordinate transformations, symmetry expansion and generation of symmetry constraints.

References

PDFgui and PDFfit2 are intended for scientific research that will be published in the open literature and are free to use. Please cite the following paper in all your scientific publications using one of our programs.

C. L. Farrow, P. Juhás, J. W. Liu, D. Bryndin, E. S. Božin, J. Bloch, Th. Proffen and S. J. L. Billinge, PDFfit2 and PDFgui: computer programs for studying nanostructure in crystals, J. Phys.: Condens. Matter 19, 335219 (2007)

Acknowledgements

Developers

The active DiffPy team is Pavol Juhás, Chris Farrow, Emil Božin, Simon Billinge, Wenduo Zhou, Peng Tian and Timur Dykhne. The project was started at the Department of Physics and Astronomy, Michigan State University. The development team has now mostly relocated to the Department of Applied Physics and Applied Mathematics at Columbia University in the city of New York. The former members of the project while at Michigan State were Jiwu Liu and Dmitriy Bryndin.

Funding

This software was developed as part of the Distributed Data Analysis of Neutron Scattering Experiments (DANSE) project funded by the US National Science Foundation under grant DMR-0520547. More information on DANSE can be found at http://danse.us. The early developments of PDFfit2 were funded by NSF grant DMR-0304391 in the Billinge-group, and with support from Michigan State University. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the respective funding bodies.

Other

www.vim.org for splendid editor and inspiration for this website.