Entropic sampling of flexible polyelectrolytes within the Wang-Landau algorithm

We extend the Monte Carlo methods developed in our previous papers [J. Phys. A 37, 1573 (2004); Macromol. Theory-Simul. 14, 491 (2005)] and based on entropic sampling within the Wang-Landau algorithm to simulation of a lattice model of flexible polyelectrolytes. We consider a strongly charged polyelectrolyte chain accompanied by neutralizing counterions on a simple cubic lattice with periodic boundary conditions. The Coulomb potential and the excluded volume condition between different ions or beads are taken into account. The obtained energy distributions make possible the calculation of canonical properties such as conformational energy, heat capacity, entropy, free energy, and mean-square end-to-end distance over a wide temperature range in a single simulation.