  We present a computational study on the topology, energetics and structural
deformations for a large number of experimentally observed defect
configurations in graphene. We find that both the number of lost hexagonal
carbon rings and introduced non-hexagonal rings increase linearly as a function
of the vacancy order (number of missing atoms). The formation energies of the
defects increase by about 2.2 eV per missing atom after an initial offset,
establishing these defects as the lowest energy vacancy configurations studied
in graphene to date. In addition, we find that even small point defects, which
have been until now assumed flat, cause graphene to bend out of plane when not
restricted into prohibitively confined geometries. This effect reaches to
relative long distances even for some of the smallest defects, significantly
reducing the stress otherwise imposed on the surrounding lattice.
