ALBERT

Description: The Inorganic Crystal Structure Database (ICSD) is the world's largest database of fully evaluated and published crystal structure data, mostly obtained from experimental results. However, the purely experimental approach is no longer the only route to discover new compounds and structures. In the past few decades, numerous computational methods for simulating and predicting structures of inorganic solids have emerged, creating large numbers of theoretical crystal data. In order to take account of these new developments the scope of the ICSD was extended in 2017 to include theoretical structures which are published in peer‐reviewed journals. Each theoretical structure has been carefully evaluated, and the resulting CIF has been extended and standardized. Furthermore, a first classification of theoretical data in the ICSD is presented, including additional categories used for comparison of experimental and theoretical information.

Description: The article discusses how theoretical crystal data are supplementing experimental data for simulation and prediction of structures of inorganic solids in the Inorganic Crystal Structure Database.

Description: RECAWA intends to develop a fundamental understanding of the reactivity and dynamics of calcite surfaces during crystal growth in aquatic systems. Therefore, the calcite-water surface has been characterised at different hydrochemical conditions and surface diffraction measurements have been applied to probe if changes in zeta potential are accompanied by changes in the calcite-water interface structure. The interaction of calcite with Selenium is investigated in a mixed flow reactor (MFR) study which is accompanied by GI- EXAFS analyses to characterize the Se adsorption species. The interaction of calcite surfaces with phosphate and phosphonates is the focus of two subprojects. The sorption/precipitation mechanisms of PO43- and HPO32+, respectively, on different calcite powders (precipitated calcium carbonates and limestone powders) are investigated to determine sorption isotherms and phase transformations on the applied surfaces which is of great interest with regard to phosphate recycling and/or water treatment. Analytical work includes SEM, XRD and XAFS spectroscopy for a detailed characterisation of the calcite powders in different sections of the isotherms. Experimental investigations on the interaction of limestone powder and two superplasticizers have been conducted with regard to concreting. These experiments were done at alkaline conditions and lead to massive reactions and changes in the zeta potential of the solutions and limestone powder when superplasticizers added. Additional results of quantum-mechanical calculations and force-field modelling demonstrated that the Double Defect Method is able to quantitatively predict mixing properties of various isostructural binary and ternary carbonate solid solutions. In particular, low equilibrium retention levels of SO42- and SeO42- in carbonates imply that the reasonably large concentrations SO42- and SeO42- in carbonates reported in previous studies should be attributed to non-equilibrium entrapment effects. Data obtained from atomistic modelling complement our data determined using lab methods. Further experimental and analytical, work including in-situ AFM studies using Iceland spar single crystals, is in progress and will help to interconnect the present results of the sub-projects.

Description: Deep-sea hydrothermal fields (HTF) associated with the formation of seafloor massive sulphides (SMS) may become a future source of high-tech metals, which are in high demand for the energy transition. The identification and evaluation of the deposits are challenging, as they are relatively small and form in complex terrain at mid-ocean ridges, island arcs, or back-arc spreading centres. Active HTFs are often accompanied by black smokers and have an abundant, environmentally sensitive fauna. Tt is generally agreed that they should be excluded from possible mining. The economically interesting inactive and extinct fields often miss the characteristic seafloor expressions and distinct vent fauna, and may be hidden under a thin layer of sediments. Thus, video observations and sampling are not sufficient to evaluate the extent of the SMS deposit.Since 2015, BGR undertakes annual research cruises to the German SMS license areas along the Indian ridges (INDEX project) with the aim to find prospective mineral deposits and establish environmental baseline studies. Several unknown HTFs have been identified using a multidisciplinary approach. An important aspect in mineral resource assessment is the inner structure and size of the deposits, which can be addressed by geophysical methods. In addition to magnetic and bathymetric surveys, we apply electromagnetic and self-potential methods on deep-sea sensor platforms. We can clearly relate electrical conductivity, magnetic and self-potential anomalies to previously identified sulphide sites of active and inactive hydrothermal areas. However, deriving spatial constraints is still one of the most challenging and vital disciplines of geophysical exploration in this context.