The Mott transition in the 5d\(^1\) compound Ba\(_2\)NaOsO\(_6:\) a DFT+DMFT study with PAW non-collinear projectors

• Published in: arXiv.org
• Main Authors: Dario Fiore Mosca, Schnait, Hermann, Celiberti, Lorenzo, Aichhorn, Markus, Franchini, Cesare
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 29.03.2023
• Subjects: Coupling (molecular); Density functional theory; Electrons; Insulation; Magnetic properties; Mean field theory; Perovskites; Projectors; Relativistic effects; Spin-orbit interactions
• DOI: 10.48550/arxiv.2303.16560

Spin-orbit coupling has been reported to be responsible for the insulating nature of the 5d\(^1\) osmate double perovskite Ba\(_2\)NaOsO\(_6\) (BNOO). However, whether spin-orbit coupling indeed drives the metal-to-insulator transition (MIT) in this compound is an open question. In this work we investigate the impact of relativistic effects on the electronic properties of BNOO via density functional theory plus dynamical mean-field theory calculations in the paramagnetic regime, where the insulating phase is experimentally observed. The correlated subspace is modeled with non-collinear projectors of the projector augumented wave method (PAW) employed in the Vienna Ab Initio Simulation Package (VASP), suitably interfaced with the TRIQS package. The inclusion of PAW non-collinear projectors in TRIQS enables the treatment of spin-orbit coupling effects fully ab-initio within the dynamical mean-field theory framework. In the present work, we show that spin-orbit coupling, although assisting the MIT in BNOO, is not the main driving force for its gapped spectra, placing this material in the Mott insulator regime. Relativistic effects primarily impact the correlated states' character, excitations, and magnetic ground-state properties.