We present a finite-size scaling analysis of the droplet
condensation-evaporation transition of a lattice gas (in two and three
dimensions) and a Lennard-Jones gas (in three dimensions) at fixed density.
Parallel multicanonical simulations allow sampling of the required system sizes
with precise equilibrium estimates. In the limit of large systems, we verify
the theoretical leading-order scaling prediction for both the transition
temperature and the finite-size rounding. In addition, we present an emerging
intermediate scaling regime, consistent in all considered cases and with
similar recent observations for polymer aggregation. While the intermediate
regime locally may show a different effective scaling, we show that it is a
gradual crossover to the large-system scaling behavior by including empirical
higher-order corrections. This implies that care has to be taken when
considering scaling ranges, possibly leading to completely wrong predictions
for the thermodynamic limit. In this study, we consider a crossing of the phase
boundary orthogonal to the usual fixed temperature studies. We show that this
is an equivalent approach and, under certain conditions, may show smaller
finite-size corrections.Comment: 12 pages, 9 figures, to appear in Phys. Rev.
