Simulation of electron energy loss spectra of nanomaterials with linear-scaling density functional theory.

Published version
Repository DOI

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Authors
Tait, EW 
Ratcliff, LE 
Payne, MC 
Haynes, PD 
Hine, NDM 
Abstract

Experimental techniques for electron energy loss spectroscopy (EELS) combine high energy resolution with high spatial resolution. They are therefore powerful tools for investigating the local electronic structure of complex systems such as nanostructures, interfaces and even individual defects. Interpretation of experimental electron energy loss spectra is often challenging and can require theoretical modelling of candidate structures, which themselves may be large and complex, beyond the capabilities of traditional cubic-scaling density functional theory. In this work, we present functionality to compute electron energy loss spectra within the onetep linear-scaling density functional theory code. We first demonstrate that simulated spectra agree with those computed using conventional plane wave pseudopotential methods to a high degree of precision. The ability of onetep to tackle large problems is then exploited to investigate convergence of spectra with respect to supercell size. Finally, we apply the novel functionality to a study of the electron energy loss spectra of defects on the (1 0 1) surface of an anatase slab and determine concentrations of defects which might be experimentally detectable.

Description
Keywords
EELS, ELNES, linear scaling, defects, titanium dioxide, theoretical spectroscopy, electron energy loss spectroscopy
Journal Title
Journal of Physics: Condensed Matter
Conference Name
Journal ISSN
0953-8984
1361-648X
Volume Title
28
Publisher
Institute of Physics Publishing
Sponsorship
Engineering and Physical Sciences Research Council (EP/J015059/1)
Engineering and Physical Sciences Research Council (EP/G037221/1)
This work was performed using the Darwin Supercomputer of the University of Cambridge High Performance Computing Service (http://www.hpc.cam.ac.uk/), provided by Dell Inc. using Strategic Research Infrastructure Funding from the Higher Education Funding Council for England and funding from the Science and Technology Facilities Council. E.W.T. was supported by the EPSRC Cambridge NanoDTC, EP/G037221/1. L.E.R. was supported, in part, by DOE Office of Science User Facility under Contract DE-AC02-06CH11357. N.D.M.H. Acknowledges the support of the Winton Programme for the Physics of Sustainability. We wish to acknowledge the use of the EPSRC's Chemical Database Service at Daresbury.