Commonly accepted, the conventional ionic model has been used for almost one century to describe inorganic solids in terms of cation-centred anionic polyhedrons.Unfortunately, the model is unable to either describe or understand why inorganic compounds adopt the structures they have.In this book, the author exposes the limitations of the ionic model and proposes new concepts, like the relation between oxidation and pressure and the extended Zintl-Klemm concept combined with Hoffmann's isolobality concept, hypervalency and the equivalence between electrons pairs and anions,to obtain a much deeper understanding of the structures of inorganic.The experimental data discussed along the text under the light of these concepts allow us to conclude that the structures of elements and alloys are present in their oxides. Sometimes deformed, sometimes unchanged, or even transformed by the laws of the Zintl-Klemm concept, elemental structures are key to understand complex structures.