  Hydrogen adatoms and other species covalently bound to graphene act as
resonant scattering centers affecting the electronic transport properties and
inducing Anderson localization. We show that attractive interactions between
adatoms on graphene and their diffusion mobility strongly modify the spatial
distribution, thus fully eliminating isolated adatoms and increasing the
population of larger size adatom aggregates. Our scaling analysis shows that
such aggregation of adatoms increases conductance by up to several orders of
magnitude and results in significant extension of the Anderson localization
length in the strong localization regime. We introduce a simple definition of
the effective adatom concentration $x^\star$ , which describes the transport
properties of both random and correlated distributions of hydrogen adatoms on
graphene across a broad range of concentrations.
