CORRECTIONS TO SCALING FOR DIFFUSION EXPONENTS ON 3-DIMENSIONAL PERCOLATION SYSTEMS AT CRITICALITY

Recent results of Monte Carlo simulations of the ant-in-the-labyrinth method in three-dimensional percolation lattices are reanalyzed in the light of more accurate corrections to scaling ansatz, motivated by inconsistent results that have appeared in the literature. The results are observed to be sensitive to the form of the scaling correction terms. Using a single correction term, we estimate the value kappa = 0.197 +/- 0.004 for the anomalous diffusion exponent at criticality. When two correction terms are included, kappa = 0.002 is obtained. These new estimates are consistent with known theoretical bounds, with recent series expansion results, and with numerical calculations of the conductance of random resistor networks above criticality.