  We present some preliminary results from a series of extremely large,
high-resolution N-body simulations of the formation of early nonlinear
structures. We find that the high-z halo mass function is inconsistent with the
Sheth-Tormen mass function, which tends to over-estimate the abundance of rare
halos. This discrepancy is in rough agreement with previous results based on
smaller simulations. We also show that the number density of minihaloes is
correlated with local matter density, albeit with a significant scatter that
increases with redshift, as minihaloes become increasingly rare. The average
correlation is in rough agreement with a simple analytical extended
Press-Schechter model, but can differ by up to factor of 2 in some regimes.
