In this work we demonstrate that maximally localized Wannier functions MLWFs based on Kohn-Sham band structures provide a very robust and systematic way to construct realistic, materials-specific tight-binding models for further theoretical analysis. In particular, we construct MLWFs for the Mn eg bands in LaMnO3, and we monitor changes in the MLWF matrix elements induced by different magnetic ...

We investigate the effects induced by the interplay of microscopic degrees of freedom. In many cases, one has to consider spin and orbital degeneracy to explain complex structures of magnetic and orbital order. Frequently, attention is focused on electronic correlations. We study how the interaction of electrons with lattice degrees of freedom modifies the pure electronic case. Because of orbit...

Magnetic anisotropy in cyanide-bridged single-molecule magnets (SMMs) with Fe(III)-CN-M(II) (M = Cu, Ni) exchange-coupled pairs was analyzed using a density functional theory (DFT)-based ligand field model. A pronounced magnetic anisotropy due to exchange was found for linear Fe(III)-CN-M(II) units with fourfold symmetry. This results from spin-orbit coupling of the [Fe(III)(CN)6](3-) unit and ...

Metal ions are both ubiquitous to and crucial in biology. In classical simulations, they are typically described as simple van der Waals spheres, making it difficult to provide reliable force field descriptions for them. An alternative is given by nonbonded dummy models, in which the central metal atom is surrounded by dummy particles that each carry a partial charge. While such dummy models al...

The interplay between the electron repulsion U and the Jahn-Teller electron-phonon interation E LR is studied with a large d model for the ferromag-netic state of the manganese oxides. These two interactions collaborate to induce the local isospin (orbital) moments and reduce the bandwidth B. Especially the retardation eeect of the Jahn-Teller phonon with the frequency is eeective to reduce B, ...