Structural and electronic properties of new 1D and 2D carbon allotropes with mixed sp1 − sp3 hybridization types

New 1D and 2D highly porous carbon allotropes are designed, which combine the atoms in sp1 and sp3 hybridization. The structural motifs of suggested compounds can emerge from the same polyyne building blocks as for experimentally fabricated expanded cubane. The structural, electronic properties and relative stability of proposed 1D and 2D carbon allotropes have been examined and discussed through the calculations on the basis of the density functional theory.