Pressure-induced incompressibility of ReC and effect of metallic bonding on its hardness

The compressible behaviors of the selected 5d transition metal carbides MC (M=W,Re,Os,Ir) with hexagonal tungsten carbide-type structure were studied by first-principles calculations. Results indicate that the incompressibility of ReC exceeds that of diamond under higher pressure. The calculated method for hardness of crystals with partial metallic bonding is suggested and the calculated results indicate that hexagonal ReC crystal possesses excellent mechanical properties.