Monte Carlo simulation of tetrahedral chains, 3. Star‐shaped polymers by pivot algorithm

Abstract

AbstractBy use of the pivot algorithum, stars with F = 3–12 arms of length n, nF = 480, and linear chains (F = 2) are generated on a tetrahedral lattice in order to test the suitability of this algorithm for star‐shaped polymers. A new configuration is obtained by rotating that part of an arm which contains the chain end around a randomly selected bond by ±120°. If no double occupancies occur, the new configuration is accepted. Otherwise, the old one is restored. The (average) acceptance fraction decreases only slightly with increasing number of arms. The probability of obtaining a new self‐avoiding configuration by a move of an arm around a bond near the centre of the star is significantly higher than the probability for a successful combination of star with F‐1 arms with a further arm. The statistical error of global properties of stars with the same total number of segments is nearly independent of the number of arms, because an increase of the autocorrelation times is approximately compensated by a decrease of mean square deviations. In principle, comparison of the data with theoretical predictions yields the same results as found for other lattice models.