New nanostructured carbon compounds based on graphyne layers

The article presents a semi-empirical and first-principle study of carbon compounds consisting of interpenetrating graphene layers called self-intercalated. As a result of calculations, the possibility of forming one-dimensional self-intercalated nanostructures and three-dimensional phases with ordered structure based on six main types of graphyne layers was studied. The most stable self-intercalated nanostructures can be formed only based on $\alpha$-grapyne-1 and $\beta$1-graphyne-2 layers which have translation parameters of 6.89 and 14.6 Å, respectively. Three-dimensional phases of this self-intercalated layers must have the tetragonal $I4/mcm$ (№ 140) or orthorombic $Ibam$ (№ 72) symmetry, channel sizes from 6.00 to \mbox{9.42 Å$ $ and densities from 0.69 to 1.26 g/cm$^3$. Molecular dynamics calculations shown that graphyne layers in the self-intercalated phase structure can be wave-like deformed \sloppy at 400 K. Experimental identification of new three-dimensional self-intercalated phases can be performed using calculated X-ray diffraction patterns and X-ray absorption spectra.