  The CLEF-SSH simulation project is an international collaboration, involving
the IAS, LATT and the University of Sussex, to produce large hydrodynamic
simulations of large-scale structure that implement realistic models of
radiative gas cooling and energy feedback. The objective is to use these
simulations to study the physics of galaxy clusters and to construct maps of
large angular size of the Sunyaev-Zel'dovich (SZ) effect, for the preparation
of future experiments. Here we present results from a first run, the CLEF
hydrodynamics simulation, which features 2(428)^3 particles of gas and dark
matter inside a comoving box with 200 Mpc/h on a side.
