Static corrections versus dynamic correlation effects in the valence band Compton profile spectra of Ni

TL;DR

This paper compares static and dynamic electronic correlation effects on the valence band Compton profiles of nickel, highlighting how different treatments of correlations significantly influence the spectral features and moments.

Contribution

It systematically analyzes the impact of static versus dynamic correlation treatments on Compton profiles of Ni within DFT, revealing qualitative and quantitative differences.

Findings

Significant differences in Compton profiles depending on correlation treatment.

Dynamic correlations modify the kinetic energy along specific directions.

The moments of profile differences depend on the Coulomb interaction strength.

Abstract

We compute the Compton profile of Ni using the Local Density Approximation of Density Functional Theory supplemented with electronic correlations treated at different levels. The total/magnetic Compton profiles show not only quantitative but also qualitative significant differences depending weather Hubbard corrections are treated at a mean field +U or in a more sophisticated dynamic way. Our aim is to discuss the range and capability of electronic correlations to modify the kinetic energy along specific spatial directions. The second and the fourth order moments of the difference in the Compton profiles are discussed as a function of the strength of local Coulomb interaction $U$.