▎ 摘　　要

By the resonance-theoretic method zigzag graphene nanoribbons are predicted to have an antiferromagnetic ground state with a Mulliken spin density of 0.33 on the edge atoms and the armchair graphene nanoribbons are predicted to have a nonmagnetic ground state. Similar calculations predict that saw-tooth graphene nanoribbons have a weakly antiferromagnetic ground state with edge atoms having a Mulliken spin density of 0.16 on the edge atoms. (C) 2008 Elsevier B.V. All rights reserved.