Valence electron distribution in MgB2 studied by accurate diffraction measurements and first principle calculations

TL;DR

This study combines synchrotron x-ray and electron diffraction techniques with first-principles calculations to accurately analyze valence electron distribution in MgB2, revealing significant deviations from free atom models and confirming the reliability of density functional theory.

Contribution

It provides experimentally validated electron density maps of MgB2, demonstrating the redistribution of valence electrons during crystal formation and confirming the accuracy of first-principles calculations.

Findings

Valence electron distribution deviates from free atom models.

Experimental structure factors agree with density functional theory calculations.

Electron density maps illustrate electron redistribution in MgB2.

Abstract

We use synchrotron x-ray and precision electron diffraction techniques to determine accurately the structure factors of selected reflections that are sensitive to the valence electron distribution in the superconductor MgB2. These values deviate significantly from calculated structure factors using the scattering factors of free atoms, but agree well with our calculated structure factors based on density functional theory. Having experimentally established the reliability of our firstprinciple calculated structure factors, we present electron density maps of the redistribution of the valence electrons that takes place when hypothetical free atoms of Mg and B in MgB2 interact to form the real crystal.