Sampling methods for Monte Carlo simulations of n-butane in dilute solution

Sampling procedures for enhancing the convergence of Monte Carlo simulations of dilute solutions have been analyzed and applied to modeling n-butane in a Lennard-Jones liquid at 25 °C. The efficiency of the procedures is compared for determining structural and thermodynamic properties of the solution including the trans–gauche equilibrium for the solute. Preferential sampling of the solute plus umbrella sampling with ’’chopped’’ rotational barriers is found to be a viable means for studying conformational equilibria in solution.