An Efficient Simulation Method for Determining the Density of States of Complex Systems

By combining two generalized-ensemble algorithms, the Multicanonical Replica-Exchange Method and the Replica-Exchange Wang-Landau method, we have developed an effective simulation method to determine the density of states of large and complex systems. In order to verify the effectiveness of our algorithm, we performed simulations of a square-lattice Ising model by several methods. The results showed that the density of states obtained by the present method is more accurate than that is estimated by the two methods used separately.