DFT+DMFT with natural atomic orbital projectors

TL;DR

This paper introduces natural atomic orbitals as a stable, self-consistent local projector for DFT+DMFT calculations, improving electron counting and reducing computational costs.

Contribution

It presents a novel approach using natural atomic orbitals as projectors in DFT+DMFT, enhancing stability, electron counting accuracy, and computational efficiency.

Findings

Natural atomic orbitals are stable against basis variations.

They enable self-consistent updates within DFT+DMFT loops.

Orbital separation reduces computational cost.

Abstract

We introduce natural atomic orbitals as the local projector to define the correlated subspace for DFT + DMFT (density functional theory plus dynamical mean-field theory) calculation. The natural atomic orbitals are found to be stably constructed against the number and the radius of basis orbitals. It can also be self-consistently updated inside the DFT+DMFT loop. The spatial localization, electron occupation and the degree of correlation are investigated and compared with other conventional techniques. As a `natural' choice to describe the electron numbers, adopting natural atomic orbitals has advantage in terms of electron number counting. We further explore the reduction of computation cost by separating correlated orbitals into two subgroups based on the orbital occupancy. Our new recipe can serve as a useful choice for DFT+DMFT and related methods.