Electronic structure and magnetic properties of correlated metals - A local self-consistent perturbation scheme

In the framework of LDA+DMFT (dynamical mean field theory) approach for realistic electronic structure calculations, a new perturbation scheme which combines the T-matrix and fluctuating exchange approximations is presented. This method is less computationally expensive than the numerically exact quantum Monte Carlo technique and give an adequate description of the electronic structure and exchange interactions in magnetic metals. We present a simple expression for the exchange interactions corresponding to the neglect of the vertex, corrections which becomes exact for the spin-wave stiffness in the local approximation. Electronic structure, correlation effects and exchange interactions for ferromagnetic nickel are discussed.