Many-electron expansion: A density functional hierarchy for strongly correlated systems

Density Functional Application to Strongly Correlated Electron Systems

The LSDA+U approach to density functional theory is carefully reanalyzed. Its possible link to single-particle Green’s function theory is occasionally discussed. A simple and elegant derivation of the important sum rules for the on-site interaction matrix elements linking them to the values of U and J is presented. All necessary expressions for an implementation of LSDA+U into a non-orthogonal ...

Strongly correlated electron systems.

Strongly correlated electron systems.

Cluster methods for strongly correlated electron systems

The development of dynamical mean field methods has resulted in significant advances in our understanding of strongly correlated electron systems, in particular in the area of the Mott transition. This method captures the local effects of correlations such as the Kondo effect and the transfer of spectral weight between the coherent and the incoherent part of the spectral function. It suffers, h...

Reduced Density Matrix Functional for Many-Electron Systems

Reduced density matrix functional theory for the case of solids is presented and a new exchange correlation functional based on a fractional power of the density matrix is introduced. We show that compared to other functionals, this produces more accurate results for finite systems. Moreover, it captures the correct band gap behavior for conventional semiconductors as well as strongly correlate...