The hole-electron analysis method proposed by us can be used to more specifically show the characteristics of the electron transition process . For the general description of hole-electron analysis method, please see the Ref. . The hole-electron distributions for the critical excitations of carbon chains are shown in Fig. . From there, we can again determine that the maximum absorptions of all carbon chains are caused by the π-π* transition, because the corresponding holes and electrons involving 1 1 Σ u + ← X 1 Σ g + excitation are distributed around the C-C bonds.