AB INITIO CALCULATIONS OF THE STRUCTURE AND ELECTRONIC PROPERTIES OF BN LAYERED COMPOUNDS FROM SP - AND SP2 - HYBRITIZED ATOMS

BN layers with a structure similar to that of graphyne were theoretically investigated by the density functional theory method in the generalized gradient approximation. The model structure of polymorphic varieties of BN layers was constructed on the basis of hexagonal boron nitride layers by replacing interatomic bonds with diatomic molecular BN fragments. As a result of theoretical analysis, the possibility of the existence of seven basic structural varieties of graphyne-like boron nitride has been established. However, with geometric optimization, only six polymorphs were stable. The structure of BN - L-6 - gamma(3) polymorph was transformed into the structure of the initial BN - L-6 layer. The sublimation energy of graphyne-like BN layers varies in the range from 16,29 to 17,00 eV/(BN ), the width of the band gap is from 2,14 to 4,02 eV. The layered density of the BN layers varies from 0,33 to 0,58 mg/(2).