Equation of states, energy band structure, electronic density of states, and bulk modula of the boron nitride fulborenite crystals: B12N12 with a diamond lattice and B24N24, B12N12 with a simple cubic lattice have been calculated for the first time by FLAPW method. Calculated parameters of hyperdiamond B12N12 are: the equililbrium lattice parameter a = 1.1191 nm, the length of B–N bond aBN = 0.1405 nm, the number of atoms per conventional cell Z = 192, density = 2.823 g/cm3, bulk modulus B0 = 658 GPa, band gap Eg = 3.05 eV. This is formerly unknown unique superhard semiconducting faujasite with the record bulk modulus higher than for a diamond. There are bases to assume that it is the E-phase. Characteristics of B24N24 with a simple cubic lattice: equilibrium lattice parameter a = 0.7346 nm, the length of B–N bond aBN = 0.1521 nm, the number of atoms in unit cell Z = 48, density = 2.495 g/cm3, bulk modulus B0 = 367 GPa, band gap Eg = 3.76 eV. It is the heteropolar semiconductor or dielectric with the bulk modulus comparable with the bulk modulus for cubic boron nitride and also new boron nitride-like zeolite with diameter of channels 0.46 nm. B12N12 with a simple cubic lattice — molecular semimetal.
Физика и техника полупроводников, 2006, том 40, вып.