Repository logo
 

Refining structures against reflection rank: an alternative metric for electron crystallography.


Type

Article

Change log

Authors

Eggeman, Alexander S 
Midgley, Paul A 

Abstract

A new metric is proposed to improve the fidelity of structures refined against precession electron diffraction data. The inherent dynamical nature of electron diffraction ensures that direct refinement of recorded intensities against structure-factor amplitudes can be prone to systematic errors. Here it is shown that the relative intensity of precessed reflections, their rank, can be used as an alternative metric for refinement. Experimental data from erbium pyrogermanate show that applying precession reduces the dynamical transfer of intensity between reflections and hence stabilizes their rank, enabling accurate and reliable structural refinements. This approach is then applied successfully to an unknown structure of an oxygen-deficient bismuth manganite resulting in a refined structural model that is similar to a calcium analogue.

Description

Keywords

structure refinement, precession electron diffraction

Journal Title

Acta Crystallogr A

Conference Name

Journal ISSN

2053-2733
1600-5724

Volume Title

Publisher

International Union of Crystallography (IUCr)
Sponsorship
Engineering and Physical Sciences Research Council (EP/H017712/1)
The authors thank the EPSRC for financial support through grant number HO17712