Electronic Correlations and Covalency: Dynamical Mean-Field Perspective
Dr. Jan Kuneš (Institute of Physics, Academy of Sciences, Praha)

The development of the dynamical mean-field theory (DMFT) lead to a breakthrough in our understanding of electronic correlations in the Hubbard model and the interaction-driven metal-insulator transition. The combination of DMFT with first-principles multi-band Hamiltonians (LDA+DMFT) uncovered a variety of behaviors stemming from interplay between the local correlations and chemical bonding. In my talk I will use LDA+DMFT results to discuss the role of transition-metal--ligand hybridization in charge-transfer materials NiO and NiS_2-xSe_x as well as the effect of electronic correlation in band insulators with a hybridization gap, a picture we believe to be relevant e.g. for FeSi.