  We study the large-scale structure with superclusters from the REFLEX X-ray
cluster survey together with cosmological N-body simulations. It is important
to construct superclusters with criteria such that they are homogeneous in
their properties. We lay out our theoretical concept considering future
evolution of superclusters in their definition, and show that the X-ray
luminosity and halo mass functions of clusters in superclusters are found to be
top-heavy, different from those of clusters in the field. We also show a
promising aspect of using superclusters to study the local cluster bias and
mass scaling relation with simulations.
