DMFTwDFT: A computational framework to capture correlated magnetism beyond DFT

Magnetism plays a crucial role in designing quantum devices and functional materials. Since magnetic moments often originate from strong electron correlations, many magnetic materials exhibit band structures intricately coupled to their spin, orbital, charge and lattice degrees of freedom. While conventional methods such as density functional theory (DFT) can be used to study magnetic properties, including the spin exchange parameters, DFT often fails to capture the strong correlation effect of the band structure. In this talk, we introduce DMFTwDFT, a computational package based on dynamical mean field theory (DMFT) combined with various DFT codes such as VASP, Siesta, and Quantum Espresso. Our code enables the study of both correlated band structures and magnetic properties of strongly correlated materials beyond DFT. Here, we will show its capability by calculating the spin exchange parameters of Na₃Co₂SbO₆ in a honeycomb lattice, which has been suggested as a possible candidate to realize the Kitaev spin liquid phase.