Comparison between the halo mass function measured from the simulations (symbols) and the fit function from Tinker et al. (2010, shown with the blue dashed lines). The red circles present the measurements from model-03 at redshift z = 0.043, while the black squares are from the SLICS simulations (hence the error bars). Lower panel: fractional error between simulations and models, where the latter is taken as the reference. The vertical lines mark the mass of dark matter haloes containing 100 particles, which varies between cosmologies due to changes in the particle mass.