Structural, elastic, and electronic properties of new superhard isotropic cubic crystals of carbon nanotubes

The models of new isotropic cubic crystals of single-layered carbon nanotubes are proposed. The structural, elastic, and electronic properties and the energies of formation of these crystals were calculated using the density functional-based tight binding (DFTB) method. The crystals proposed were found to exhibit extreme compression moduli (550–650 GPa) and a minimum compressibility (0.0018–0.0015 GPa⁻¹); in this case, the type of conduction of the parent nanotubes was retained. For this reason, the above crystals are of interest for the development of new superhard materials with controllable electrophysical properties.