Electronic structure, chemical bonding, and properties of binary carbides MxM′yCz in the crystalline and molecular states:: XES, XPS, and quantum-chemical studies

This paper reviews the results of electronic structure studies and investigations of the nature of chemical bonding and properties of binary d-metal carbides in the crystalline and molecular states. X-ray emission and X-ray photoelectron spectroscopy as well as quantum-chemical data arc analyzed, and variations of the electronic properties and interatomic interactions are discussed for carbides of high-melting metals doped on the metal sublattice and a series of their reciprocal solid solutions: NbC-TaC, TiC-VC0.87 TiC-NbC, and NbC-MOC0.67 over a wide range of compositions. Prospects are discussed for application of quantum-chemical methods to structure and property modeling and forecasting for a new class of molecular clusters - binary metallocarbohedrenes M8-nMnC12 and related metal-carbon nanoparticles of "mixed" composition.