Local electronic structure analysis for brownmillerite Ca(Sr)FeO2.5 using site-resolved energy-loss near-edge structures

Core-hole effects on energy-loss near-edge structure.

We present first-principles electron energy-loss near-edge structure calculations that incorporate electron-hole interactions and are in excellent agreement with experimental data obtained with X-ray absorption spectroscopy (XAS) and electron energy-loss spectroscopy (EELS). The superior energy resolution in XAS spectra and the new calculations make a compelling case that core-hole effects domi...

Simulating the energy-loss near edge structure for interferometric EELS in reciprocal space

First-principles calculation of the electronic structure and energy loss near edge spectra of chiral carbon nanotubes.

We present first principles calculations of the electronic structure of small carbon nanotubes with different chiral angles theta and different diameters (d<1 nm). Results are obtained with a full potential method based on the density functional theory (DFT), with the local density approximation (LDA). We compare the band structure and density of states (DOS) of chiral nanotubes with those of z...

Spatially Resolved Electron Energy-Loss Spectroscopy, a Tool to Verify Electronic Structure Calculations in Nanostructured Materials

Modern mcroscopy allows a direct comparison between experimental results and the atomic and electronic structure as obtained by state of the art ab-initio calculations. The phase reconstruction technique allows one to determine the positions of atomic columns with an accuracy of about 30pm. The atomic structure can be studied directly (without computer simulation or reconstruction) with Z-contr...

First-principles Calculation of L3 X-ray Absorption Near Edge Structures (XANES) and Electron Energy Loss Near Edge Structures (ELNES) of GaN and InN Polymorphs

First principles calculations of L3 XANES/ELNES of GaN and InN with both wurtzite and zinc-blende structures have been made using OLCAO (orthogonalized linear combinations of atomic orbitals) method. Supercells with more than 100 atoms were employed. A core-hole was rigorously included in the calculation, and the photo absorption cross section (PACS) between the initial and final states was com...