EDP2PDF: a computer program for extracting a pair distribution function from an electron diffraction pattern for the structural analysis of materials

Hongwei Liu; Keita Nomoto; Anna V Ceguerra; Jamie J Kruzic; Julie Cairney; Simon P Ringer

doi:10.1107/S1600576723004053

EDP2PDF: a computer program for extracting a pair distribution function from an electron diffraction pattern for the structural analysis of materials

J Appl Crystallogr. 2023 May 31;56(Pt 3):889-902. doi: 10.1107/S1600576723004053. eCollection 2023 Jun 1.

Authors

Hongwei Liu¹, Keita Nomoto^{2

3}, Anna V Ceguerra^{1

2}, Jamie J Kruzic³, Julie Cairney^{1

2}, Simon P Ringer^{1

2}

Affiliations

¹ Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia.
² School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006, Australia.
³ School of Mechanical and Manufacturing Engineering, UNSW Sydney, Sydney, New South Wales 2052, Australia.

Abstract

Pair distribution function (PDF) analysis is a powerful technique to understand atomic scale structure in materials science. Unlike X-ray diffraction (XRD)-based PDF analysis, the PDF calculated from electron diffraction patterns (EDPs) using transmission electron microscopy can provide structural information from specific locations with high spatial resolution. The present work describes a new software tool for both periodic and amorphous structures that addresses several practical challenges in calculating the PDF from EDPs. The key features of this program include accurate background subtraction using a nonlinear iterative peak-clipping algorithm and automatic conversion of various types of diffraction intensity profiles into a PDF without requiring external software. The present study also evaluates the effect of background subtraction and the elliptical distortion of EDPs on PDF profiles. The EDP2PDF software is offered as a reliable tool to analyse the atomic structure of crystalline and non-crystalline materials.

Keywords: computer programs; electron diffraction patterns; pair distribution functions.

Grants and funding

We thank the Australian Research Council for funding this work under the Discovery Grant programme (DP180101393).