A hierarchical algorithm for polymer simulations

Abstract

A computationally efficient method to evaluate the interaction energy of a polymer configuration is presented. New polymer conformations are generated via the pivot algorithm. The method involves a hierarchical search scheme for determining intersections and nonbonded nearest-neighbor contacts. The search uses a hierarchy of spheres which enclose segments of the polymer chain. At each level of the hierarchy the spheres enclose successively smaller polymer segments. This technique is found to be very efficient in terms of CPU time. It scales as 𝒪(N), where N is the polymer length, and is independent of φ, the interaction energy parameter. The method is readily applicable to off-lattice polymer models and results for both lattice and off-lattice simulations are presented.