Abstract:

In this study, we employed a density functional theory to perform self-consistent calculations on rutile-structured RuO₂. The results reveal that when electronic correlation effects are included, RuO₂ exhibits antiferromagnetic ordering with alternating magnetic characteristics; however, without these effects, RuO₂ remains nonmagnetic. A comparison between the results of the NMTO(Nth-order muffin-tin orbital) method and those obtained using the pseudopotential plane-wave method in VASP(Vienna ab-initio simulation package) indicated that the NMTO method can effectively describe the physical properties of the loosely packed rutile structure of RuO₂. Additionally, by combining the NMTO method with its unique downfolding technique, we successfully obtained tight-binding model parameters for Ru d-electronic orbitals. These parameters are highly consistent with those derived from VASP combined with maximally localized Wannier functions, showing minimal differences. This study demonstrates that the NMTO method can accurately describe the properties of RuO₂ and provide reliable tight-binding parameters via its downfolding technique, thereby providing a deeper understanding of the physical properties of the material.

Key words: density functional theory calculations, rutile-structured RuO₂, NMTO method