Multidimensional generalized-ensemble algorithms for complex systems

摘要: We give general formulations of the multidimensional multicanonical algorithm, simulated tempering, and replica-exchange method. generalize original potential energy function E(0) by adding any physical quantity V interest as a new term. These generalized-ensemble algorithms then perform random walk not only in space but also space. Among three algorithms, method is easiest to because weight factor just product regular Boltzmann-like factors, while factors for algorithm tempering are priori known. simple procedure obtaining these two latter which uses short simulation multiple-histogram reweighting techniques. As an example applications we have performed two-dimensional simulated-tempering using alpha-helical peptide system. From simulations, study helix-coil transitions gas phase aqueous solution.