Distribution of the MCXC clusters in the z–L₅₀₀ plane (Piffaretti et al. 2011). Redshift and L₅₀₀, the luminosity within R₅₀₀, are from the updated MCXC catalogue (Sadibekova et al. 2024). Each cluster is colour-coded according to the survey from which the luminosity is taken. Clusters with XMM-Newton observations are marked with red circles and those included in the EXCPReS sample are marked with red boxes. The dotted lines mark the [0.1–2.4] keV band flux taking into account the K_z correction for a typical gas temperature of 5 keV. Levels are separated by 2 dex, from 1.25 × 10⁻¹³ up to 4 × 10⁻¹² ergs s⁻¹ cm⁻2.