A detailed electronic structure study of Vanadium metal by using different beyond-DFT methods

TL;DR

This study compares various beyond-DFT methods to accurately describe the electronic structure of Vanadium, highlighting the importance of many-body theories for explaining experimental spectra in simple metals.

Contribution

It provides a comprehensive analysis of Vanadium's electronic structure using multiple advanced methods and evaluates their accuracy against experimental data.

Findings

DFT+DMFT accurately explains spectral dips due to incoherent states

W and U values from cRPA are consistent with method accuracy

DFT+GW0 shows less agreement with experimental spectra

Abstract

We report a detailed electronic structure calculation for Vanadium (V) using DFT, DFT+$U$, $G_0W_0$, $GW_0$ and DFT+DMFT methods. The calculated values of $W$, $U$ and $J$ by cRPA method are $\sim$1.1, $\sim$3.4 and $\sim$0.52 eV, respectively. The comparison between calculated spectra (CS) and experimental spectra (ES) suggests that $W$ ($U$) is more accurate for DFT+$U$ (DFT+DMFT) method. The CS, obtained by these methods, give fairly good agreement with ES for peaks' positions except $GW_0$. The shallowness of the dips lying $\sim$ -1.5 eV and $\sim$1.0 eV in ES are properly explained by DFT+DMFT method only, due to the presence of incoherent $t_{2g}$ states. This work suggests that for the proper explanation of ES, sophisticated many-body theory is needed even for the simple metal.