We simulate the two dimensional (2d), simple square and three-dimensional (
3d), simple cubic random site percolation systems for L = 2 000 000 (2d) an
d L = 10001 (3d) at the percolation thresholds for these systems. We report
excellent agreement with the Fisher exponent, tau, in 2d, with the propose
d exact value 187/91 and good agreement with other good high quality simula
tion results in 3d of 2.186. We have also computed how the first, second, t
hird,..., largest clusters scale with L at the percolation threshold. These
clusters all scale with the same fractal dimensionality as the largest clu
ster. (C) 1999 Elsevier Science B.V. All rights reserved.