Ab initioprediction of the low-temperature phase diagrams in the systems KBr–NaBr, KX–RbX, and LiX–RbX (X=Cl,Br)

Conceptual inorganic materials discovery - a road map

Synthesis of novel solids, which is a pivotal starting point in innovative materials research, is markedly impeded by the lack of predictability. A conception is presented that enables syntheses of new materials to be rationally planned. The approach is based on the atomic configuration space, and the potential energies associated to the atomic arrangements. Each minimum of the respective hyperspace of potential energy corresponds to a chemical compound capable of existence. Thus the whole realm of known and not-yet-known chemical compounds is represented in virtuo on that energy landscape. From this view it follows further that the full sets of the corresponding materials' properties are pre-determined. Within the scope of the "Energy Landscape Concept of Chemical Matter" presented, targets for synthesis are identified in a rational manner by searching the underlying potential energy landscapes for (meta)stable candidates computationally. Subsequently, the gained information are transferred to finite temperatures, which enables phase diagrams to be calculated, including metastable manifestations of matter, from first principles. The subsequent steps in materials discovery, e.g., assessing the properties and the impact of defects on the performance of the solids predicted are addressed briefly. The approach presented is complete and physically consistent; its feasibility has been proven and validated experimentally.

Role of the Li+node in the Li-BH4substructure of double-cation tetrahydroborates

The phase diagram LiBH4–ABH4(A= Rb,Cs) has been screened and revealed ten new compounds LiiAj(BH4)i+j(A= Rb, Cs), withi,jranging between 1 and 3, representing eight new structure types amongst homoleptic borohydrides. An approach based on synchrotron X-ray powder diffraction to solve crystal structures and solid-state first principles calculations to refine atomic positions allows characterizing multi-phase ball-milled samples. The Li-BH4substructure adopts various topologies as a function of the compound's Li content, ranging from one-dimensional isolated chains to three-dimensional networks. It is revealed that the Li+ion has potential as a surprisingly versatile cation participating in framework building with the tetrahydroborate anion BH4as a linker, if the framework is stabilized by large electropositive counter-cations. This utility can be of interest when designing novel hydridic frameworks based on alkaline metals and will be of use when exploring the structural and coordination chemistry of light-metal systems otherwise subject to eutectic melting.