  We present a technique to construct a fair sample of simulated galaxy
clusters, and build such a sample for a specific cosmological structure
formation scenario. Conventionally one extracts such a sample from a single
low-resolution large-scale simulation. Here we simulate the clusters
individually at high resolution. We construct a model catalogue selected on
expected final cluster mass. Such a catalogue will not have a well-defined
richness limit, because the relation between richness and mass is fairly broad.
However, by applying the appropriate completeness corrections, the results for
the mass-selected catalogue can be compared with observations for
richness-selected cluster catalogues. We build a model cluster catalogue for
the Omega_0=1 CDM scenario that is designed to mimic the ENACS sample of rich
Abell clusters. We use the distribution of richness, corrected for
incompleteness, to fix the present epoch. We find sigma_8=0.4-0.5, which is
consistent with other determinations. The catalogue is 70 per cent complete for
a richness larger than 50, but we do have a complete subsample for a richness
limit of 75. As a first test we compare the cumulative distribution of
line-of-sight velocity dispersions to those found for several observational
samples, and find that they match best for a value of around 0.4 for sigma_8.
This means that we find consistent values for sigma_8 for the CDM Omega_0=1
scenario on cluster scales.
