The relevant characteristics are consistent with the electronic transition properties of cyclocarbons . Fig. also shows that the distributions of hole and electron are relatively more localized and concentrated at the center of the carbon chains during the 1 1 Σ u + ← X 1 Σ g + excitation, instead of being uniformly distributed along the whole chains. This illustrates that the π-electron conjugations at the middle of carbon chains are stronger than those at both ends, which is consistent with their geometrical features. In addition, the highly overlapping hole and electron distributions are extremely similar to the relevant characteristics of cyclo carbon , explaining reason for the ultra-strong absorptions, that is, significantly large oscillator strengths, of carbon chains. Green and blue regions denote the hole and electron distributions, respectively.