Spin-Unrestricted Calculations of Bare-Edged Nanographenes Using DFT and Many-Body Perturbation Theory

摘要

The ability of Density Functional Theory to predict the electronic and magnetic properties of semi-infinite graphene with a single bare edge has been probed.In order to improve the accuracy of spin-unrestricted calculations performed with semilocal density functionals,higher-level methods including double hybrid density func-tionals and many-body perturbation theory have been applied to the polycyclic aromatic hydrocarbons model systems. We show that the antiferromagnetic or ferromag-netic tendencies of the corresponding electronic ground states strongly depend on the choice of the density functional. In addition the relative stability of the armchair and zigzag edges has been investigated, emphasizing the importance of using methods beyond semilocals density functionals.