First-Principles Approach to the Electronic Structure of Strongly Correlated Systems: Combining the $GW$ Approximation and Dynamical Mean-Field Theory

We propose a dynamical mean-field approach for calculating the electronic structure of strongly correlated materials from first principles. The scheme combines the $GW$ method with dynamical mean-field theory, which enables one to treat strong interaction effects. It avoids the conceptual problems inherent to conventional “$\mathrm{L}\mathrm{D}\mathrm{A}+\mathrm{D}\mathrm{M}\mathrm{F}\mathrm{T}$,” such as Hubbard interaction parameters and double-counting terms. We apply a simplified version of the approach to the electronic structure of nickel and find encouraging results.

Figure 1

Partial density of states of $d$ orbitals of nickel (solid [dashed] lines give the majority [minority] spin contribution) as obtained from the combination of $GW$ and DMFT (see text). For comparison with LDA and $\mathrm{L}\mathrm{D}\mathrm{A}+\mathrm{D}\mathrm{M}\mathrm{F}\mathrm{T}$ results, see 8; for experimental spectra, see 5.

Figure 2

Band structure of Ni (minority and majority spins) from $GW+\mathrm{D}\mathrm{M}\mathrm{F}\mathrm{T}$ as described in the text (dots) in comparison to the LDA band structure (dashed lines) and experiments [24] (triangles down) and 5 (triangles up).