Full orbital calculation scheme for materials with strongly correlated electrons

TL;DR

This paper introduces a comprehensive ab initio computational scheme for strongly correlated materials that combines Wannier functions, constrained LDA, and DMFT to accurately predict electronic properties and charge densities.

Contribution

It presents a fully self-consistent method integrating Wannier functions with many-body techniques for correlated materials, enabling detailed property calculations.

Findings

Successfully applied to SrVO3 and V2O3

Achieved improved agreement with experimental spectra

Demonstrated self-consistent charge density calculations

Abstract

We propose a computational scheme for the ab initio calculation of Wannier functions (WFs) for correlated electronic materials. The full-orbital Hamiltonian H is projected into the WF subspace defined by the physically most relevant partially filled bands. The Hamiltonian H^{WF} obtained in this way, with interaction parameters calculated by constrained LDA for the Wannier orbitals, is used as an ab initio setup of the correlation problem, which can then be solved by many-body techniques, e.g., dynamical mean-field theory (DMFT). In such calculations the self-energy operator \Sigma(e) is defined in WF basis which then can be converted back into the full-orbital Hilbert space to compute the full-orbital interacting Green function G(r,r',e). Using G(r,r',e) one can evaluate the charge density, modified by correlations, together with a new set of WFs, thus defining a fully self-consistent scheme. The Green function can also be used for the calculation of spectral, magnetic and electronic properties of the system. Here we report the results obtained with this method for SrVO3 and V2O3. Comparisons are made with previous results obtained by the LDA+DMFT approach where the LDA DOS was used as input, and with new bulk-sensitive experimental spectra.