Self-consistency over the charge-density in dynamical mean-field theory: a linear muffin-tin implementation and some physical implications

TL;DR

This paper introduces a straightforward implementation of dynamical mean-field theory with full charge density self-consistency using a linear muffin-tin orbital basis, demonstrating its importance for accurately modeling strongly correlated materials like cerium oxides.

Contribution

It presents a new, simplified method for achieving full charge density self-consistency in DMFT calculations with a linear muffin-tin orbital basis, including energy calculations and physical implications.

Findings

Full self-consistency affects thermodynamical properties.

Method applied to Ce2O3 and cerium metal.

Highlights importance of correlation-induced charge modifications.

Abstract

We present a simple implementation of the dynamical mean-field theory approach to the electronic structure of strongly correlated materials. This implementation achieves full self-consistency over the charge density, taking into account correlation-induced changes to the total charge density and effective Kohn-Sham Hamiltonian. A linear muffin-tin orbital basis-set is used, and the charge density is computed from moments of the many body momentum-distribution matrix. The calculation of the total energy is also considered, with a proper treatment of high-frequency tails of the Green's function and self-energy. The method is illustrated on two materials with well-localized 4f electrons, insulating cerium sesquioxide Ce2O3 and the gamma-phase of metallic cerium, using the Hubbard-I approximation to the dynamical mean-field self-energy. The momentum-integrated spectral function and momentum-resolved dispersion of the Hubbard bands are calculated, as well as the volume-dependence of the total energy. We show that full self-consistency over the charge density, taking into account its modification by strong correlations, can be important for the computation of both thermodynamical and spectral properties, particularly in the case of the oxide material.