Calculation of bulk modulus on carbon nitrides with chemical bond method

The bulk moduli of some superhard materials were calculated by using the chemical bond method. For simple crystals, such as diamonds, c-BN, SiC, Si, BP, and Ge, the calculated results agree with experimental and theoretical values. For crystals of complex structure, such as beta-BC(2)N crystal and various structural C(3)N(4) crystals, the results indicate that their bulk moduli are large, but do not exceed that of diamond. (c) 2007 American Institute of Physics.