Density Function Theory (DFT), are reviewed. Classic carbon allotropes, graphenes, carbon
nanotubes, fullerenes and their hybrids are being studied using DFT and related methods,
resulting a host of potentially existing forms based on 5‐, 6‐, 7‐member cycles and their
distinct combinations. Also known are cyclocarbons and large carbon clusters, nanobelts
and nanoribbons, liquid, metallic, semiconductive and superhard carbons, which could exist …