ELECTRON-ENERGY STRUCTURE OF BORON-NITRIDE AND DIAMOND - SIMILARITIESAND DISTINCTIONS

With the coherent potential method of the multiple scattering theory t he electronic structure of boron nitride (in sphalerite modification) and diamond is calculated. The cluster approximation with muffin-tin c rystal potential is used. The electron structure and chemical bonding of these substances are investigated for the first time with this mode rn theoretical method. It is shown that the chemical bonding has mainl y covalent character, the ionicity being about 20%. A fine structure o f the upper part of the valence band of boron nitride is revealed and its nature is discussed. The similarity of the total electron state de nsities of the diamond and boron nitride in sphalerite modification is proved and the distinctions are discussed. The calculated local parti al electron densities of states are used to explain the experimental X -ray emission and X-ray photoemission spectra of diamond and boron nit ride.