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This content will become publicly available on April 20, 2016

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

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. As a result, 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.
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [4]
  1. Cavendish Lab., Cambridge (United Kingdom)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
  3. Imperial College, London (United Kingdom)
  4. Univ. of Warwick, Coventry (United Kingdom)
Publication Date:
OSTI Identifier:
1248244
Grant/Contract Number:
AC02-06CH11357
Type:
Published Article
Journal Name:
Journal of Physics. Condensed Matter
Additional Journal Information:
Journal Volume: 28; Journal Issue: 19; Journal ID: ISSN 0953-8984
Publisher:
IOP Publishing
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
Argonne National Laboratory - Argonne Leadership Computing Facility; USDOE
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; EELS; ELNES; linear scaling; defects; titanium oxide; theoretical spectroscopy; electron energy loss spectroscopy