Sample of clusters with masses > 6 × 10¹⁴ M_⊙ plotted by their concentration parameter c vs. their centroid shift w from Cuciti et al. (2015). Red dots indicate clusters hosting radio haloes and black dots indicate clusters without radio haloes. The three blue points represent Abell 1314, Abell 1319, and Z7215. The w and c parameters of all clusters are computed from Chandra X-ray images, except for Abell 1314 and Z7215, which have parameters computed from XMM-Newton images. Our selected clusters have masses lower than the sample from Cuciti et al. (2015).