First-principle calculations for Mn atoms and MnO3(4) superhalogen clusters incorporated in graphene were performed to determine whether MnO3(4) superhalogen cluster doping was more thermodynamically stable than Mn atom doping. The formation energies for neutral MnO3(4) clusters embedded in graphene were all negative. Results also showed that MnO3(4) clusters embedded more easily in graphene than in Mn atoms. Given the high electronegativity of superhalogen, the charge transfer direction was always from graphene to MnO3(4) cluster. (C) 2014 Elsevier B.V. All rights reserved.