▎ 摘　　要

We revisit the model of graphene as a -conjugated macromolecule (GMM) [Phys. Rev. Lett. 2008, 100, 186806], and show that it allows us to understand the origin and describe, in many cases explicitly, the electronic structure of graphene sheets, achiral graphene ribbons and carbon tubes of any size, and additionally, achiral graphene rings and tori by using the exact solutions to the (derived previously) pair of equations slightly modified for the respective families of graphene derivatives. The exact expressions of dispersion relations for these structures are compared with the predictions of other related models demonstrating that GMM either suggests the exact versions of widely used approximations or shows their limited applicability. A complementing set of exact and approximate formulas is also added to the previously obtained results.