Quantitative Uncertainty Analysis for Diffraction (QUAD)

Documentation Status build zenodo

This is a research tool that allows analysis of X-ray and neutron diffraction data to infer the structure of materials with quantifiable uncertainty. QUAD uses Bayesian statistics and Markov chain sampling algorithms, together with components from the open source GSAS-II package, to create posterior probability distributions on all material structure parameters modeled by researchers.

While the tool has been used for several research projects, a formal Python package is still under development. Please contact rabrough@ncsu.edu with any questions.

Installation

The package can be installed by executing the following command in a terminal

pip install git+https://github.com/rabroughton/QUAD.git

The package requires the GSAS-II software. Installation instructions can be found at the GSAS-II home page.

For use in a python script, the GSAS-II path must be appended.

import sys
sys.path.append('<path>/GSASII')
# May need to append one or both of these paths
sys.path.append('<path>/GSASII/fsource')
sys.path.append('<path>/GSASII/bindist')

Authors: Susheela Singh, Christopher M. Fancher, Alyson Wilson, Brian Reich, Zhen Han, Ralph C. Smith, and Jacob L. Jones

Maintainers: Rachel A. Broughton and Paul R. Miles

Funding:

  • NSF: DMR-1445926 (RADAR Project ID 2014-2831)

  • Consortium for Nonproliferation Enabling Capabilities [Department of Energy, National Nuclear Security Administration]: DE-NA0002576 (RADAR Project ID 2014-0501)

Acknowledgement: This product includes software produced by UChicago Argonne, LLC under Contract No. DE-AC02-06CH11357 with the Department of Energy.

License:

Resources

Citing QUAD

Fancher, C. M., Han, Z., Levin, I., Page, K., Reich, B. J., Smith, R. C., Wilson, A. G., Jones, J. L. (2016). Use of Bayesian Inference in Crystallographic Structure Refinement via Full Diffraction Profile Analysis. Scientific Reports, 6, 31625. Retrieved from https://doi.org/10.1038/srep31625

Additionally, please cite the appropriate Zenodo archive for the version of QUAD that you are using.

Contents:

Indices and tables