Final Report Summary - CORRELMAT (Predictive electronic structure calculations for materials with strong electronic correlations: long-range Coulomb interactions and many-body screening) Materials with strong electronic Coulomb correlations present unique electronic properties such as exotic magnetism, charge or orbital order, or unconventional optical or transport properties, including superconductivity, thermoelectricity or metal-insulator transitions. The concerted behavior of the electrons in these "correlated materials" moreover leads to an extreme sensitivity to external stimuli such as changes in temperature, pressure, or external fields. This tunability of even fundamental properties is both a harbinger for technological applications and a challenge to currently available theoretical methods: Indeed, these properties are the result of strong electron-electron interactions and subtle quantum correlations, and cannot be understood without a proper description of excited states. Within the CORRELMAT project we have elaborated, implemented and tested new approaches to investigate the spectral and optical properties of correlated materials “from first principles”. Building on the success of state-of-the-art dynamical mean field-based electronic structure techniques, we have worked towards promoting them into truly first-principles methods, by providing explicit links between the full long-range Coulomb interactions and effective local but dynamical Hubbard interactions. At the same time, non-local effects of (screened) exchange and (spin-fluctuation-driven) correlations have been analysed. We have targeted a wide range of materials systems for benchmarks, ranging from transition metal oxides, sulphides and pnictides to rare earth compounds, as well as low-dimensional surface and interface systems. While the main focus has been put on spectroscopic properties (in comparison to experimental measurements), some of these systems have also been investigated for their magnetic properties. The CORRELMAT project has thus established an important selection of benchmark materials addressed with first-principles techniques, bringing us closer to the dream of tailoring correlated materials with preassigned properties.
