An introduction to the calculation of valence EELS: quantum mechanical methods for bulk solids

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Materials Science

Background:

• Valence electron energy-loss spectroscopy (EELS) probes the electronic structure and optical properties of materials.
• The spectral intensity in the low-loss region of EELS correlates with the complex dielectric function of bulk materials.
• Interpreting fine spectral details and linking them to material properties often requires theoretical support.

Purpose of the Study:

• To provide a theoretical overview for calculating valence EELS in bulk solids.
• To detail the practical application of these calculations using the WIEN2k code.
• To demonstrate the utility of ab initio calculations in understanding material properties through EELS.

Main Methods:

• Overview of the theoretical framework for calculating valence EELS.
• Practical guide for performing valence EELS calculations using the WIEN2k software package.
• Comparative analysis of EELS spectra for gold (Au) and its intermetallic compound AuAl(2).

Main Results:

• Ab initio quantum mechanical calculations are crucial for interpreting EELS spectral features.
• The WIEN2k code enables the computation of valence EELS spectra for bulk materials.
• Calculations successfully reproduced the main spectral details for Au and AuAl(2), correlating them with their distinct optical properties.

Conclusions:

• Theoretical calculations of valence EELS provide valuable insights into the electronic structure of materials.
• The WIEN2k code is a capable tool for performing these ab initio calculations.
• This approach effectively explains the origin of differing optical properties, such as the distinct colors of Au and AuAl(2).