Energy Landscapes of Perfect and Defective Solids: from Structure Prediction to Ion Conduction

The energy landscape concept is increasingly valuable in understanding and unifying the structural, thermodynamic and dynamic properties of inorganic solids. We present a range of examples which include (i) structure prediction of new bulk phases including carbon nitrides, phosphorus carbides, LiMgF₃ and low-density, ultra-flexible polymorphs of B₂O₃, (ii) prediction of graphene and related forms of ZnO, ZnS and other compounds which crystallise in the bulk with the wurtzite structure, (iii) solid solutions, (iv) understanding grossly non-stoichiometric oxides including the superionic phases of δ-Bi₂O₃ and BIMEVOX and the consequences for the mechanisms of ion transport in these fast ion conductors. In general examination of the energy landscapes of disordered materials highlights the importance of local structural environments, rather than sole consideration of the average structure.