Thermochemical stability of covalent and ionic inorganic compounds: Graphite-like structures, compound semiconductors, and High-T-c oxides

Based on the idea that there is a distinct boundary between structures with directed and nondirected bonding, two radically different approaches were proposed to calculating the standard enthalpies of formation of molecules a nd crystals of predominantly covalent and predominantly ionic substances-on e relying on the additivity principle, and the other on the energy-ratio me thod. These approaches were used to assess the thermochemical stability of alkali halides, high-T-c oxides, II-V and III-V semiconductors, and carbon nanostructures (fullerenes, nanotubes, capsulenes, and toroids). The result s agree well with the available experimental data.