According to widely-held beliefs the preparation of new solid state compounds based on rational design is supposed to be not possible. Thus follows the explorative character of research in synthetic solid state chemistry, with mostly unpredictable results, a situation that is experienced by each solid state chemist as stimulating or frustrating depending on his personal attitude. We present a concept that points the way towards a rational design of syntheses in solid state chemistry. The foundation of our approach is the representation of the whole material world, i.e. the known and not-yet-known compounds, on an energy landscape, which implies information about the free energies of these compounds. From this follows at once that all chemical compounds capable of existence (both thermodynamically stable and metastable ones) are already present in virtuo on this landscape. Thus the chemical synthesis always corresponds to the discovery of compounds, not their creation.

Up to now, materials capable of existence are discovered in the course of an experimental exploration of the energy landscape; however, an a priori identification of a synthesis goal requires an exploration using theoretical methods. In contrast to those computational approaches currently employed for structure determination for fixed composition and already known unit cell, our aims clash with such restrictions, and full global optimizations have to be performed on the landscape. Although for reasons of computational feasibility the accuracy of the energy calculations is not yet as high as one would wish, our approach proves to be surprisingly robust. One always finds the already known compounds of a given chemical system, and, in addition, further plausible structure candidates are discovered.