Electronic structure of V2O3: Wannier orbitals from LDA-$N$MTO calculations

TL;DR

This paper constructs Wannier orbitals for V2O3 using NMTO-downfolding within LDA, revealing that in-plane and vertical hopping interactions are equally important, challenging previous beliefs about the material's electronic regime.

Contribution

It introduces a Wannier orbital construction method for V2O3's t2g bands using NMTO-downfolding, highlighting the significance of in-plane hopping interactions.

Findings

In-plane hopping interactions are as important as vertical pair hopping.

V2O3 falls into the atomic regime rather than the molecular regime.

Hopping interactions do not change dramatically between phases.

Abstract

Using muffin-tin orbital (MTO) based NMTO-downfolding procedure within the framework of local density approximation, we construct the Wannier orbitals for the $t_{2g}$ manifold of bands in V2O3 in the paramagnetic phase. The real space representation of the one-electron Hamiltonian in the constructed Wannier function basis shows that, contrary to the popular belief, the in-plane hopping interactions are as important as the vertical pair hopping. Following the language of Di Matteo {\it et.al.} [Phys. Rev. B 65, 054413 (2002)], this implies, the problem of V2O3 falls in the atomic regime rather than in the molecular regime. We have also repeated our construction procedure in the low temperature monoclinic phase, for which the changes in hopping interactions are found not to be dramatic.