  We study the equilibrium properties of a flexible homopolymer where
consecutive monomers are represented by impenetrable hard spheres that are
tangent to each other, and non-consecutive monomers interact via a square-well
potential. To this aim, we use both replica exchange canonical simulations and
micro-canonical Wang-Landau techniques for relatively short chains, and perform
a close comparative analysis of the corresponding results. These investigations
are then further exploited to reproduce, at a much shorter scale and, hence,
computational effort, the phase diagram previously studied with much longer
chains. This opens up the possibility of improving the model and introduce
specificities typical, among other examples, of protein folding.
