  We have performed multicanonical simulations of hydrophobic-hydrophilic
heteropolymers with a simple effective, coarse-grained off-lattice model to
study the structure and the topology of the energy surface. The multicanonical
method samples the whole rugged energy landscape, in particular the low-energy
part, and enables one to better understand the critical behaviors and visualize
the folding pathways of the considered protein model.
