摘要:Searching for novel functional carbon materials is an enduring topic of scientific investigations, due to its diversity of bonds, including sp -, sp 2-, and sp 3-hybridized bonds. Here we predict a new carbon allotrope, bct-C12 with the body-centered tetragonal I 4/ mcm symmetry, from the compression of carbon nanotubes. In particular, this structure behaviors as the Dirac fermions in the k z direction and the classic fermions in the k x and k y directions. This anisotropy originates from the interaction among zigzag chains, which is inherited from ( n , n )-naotubes.