  We investigate the internal structure of clusters of galaxies in
high-resolution N-body simulations of 4 different cosmologies. There is a
higher proportion of disordered clusters in critical-density than in
low-density universes, although the structure of relaxed clusters is very
similar in each. Crude measures of substructure, such as the shift in the
position of the centre-of-mass as the density threshold is varied, can
distinguish the two in a sample of just 20 or so clusters; it is harder to
differentiate between clusters in open and flat models with the same density
parameter. Most clusters are in a quasi-steady state within the virial radius
and are well-described by the density profile of Navarro, Frenk & White (1995).
