▎ 摘　　要

We have quantitatively investigated the relationship between the aromaticity and structural stability of graphene nanoflakes (GNFs) using first-principles calculations. The aromaticity of each six-membered ring of GNFs is evaluated with the nucleus-independent chemical shifts (NICS). We have found that for armchair-edge GNFs, the degree of stability, that is, the edge formation energy, is proportional to the average NICS for all six-membered rings. Even for nitrogen-and boron-doped GNFs, the average NICS strongly correlates with the doping formation energy. Our results indicate that NICS is a good measure not only for the aromaticity but also for the structural stability of pristine/doped nanographene systems. (C) 2018 The Japan Society of Applied Physics