Multimodality of rich clusters from the SDSS DR8 within the
  supercluster-void network (talk at MG13 meeting)
  We study the relations between the multimodality of galaxy clusters drawn
from the SDSS DR8 and the environment where they reside. We find that
multimodal clusters reside in higher density environment than unimodal
clusters. We determine morphological types of superclusters and show that
clusters in superclusters of spider morphology have higher probabilities to
have substructure and larger peculiar velocities of their main galaxies than
clusters in superclusters of filament morphology. Our study shows the
importance of the role of superclusters as high density environment which
affects the properties of galaxy systems in them.
