Reaction-limited cluster-cluster aggregation is investigated using three different models. Simulations of these models suggest that (i) the fractal dimension for mobility-dependent processes is sensitive to the details of the model, (ii) the reaction kernel $K\left(\mathrm{ii}\right)\mathrm{}\sim i^{1.1}$, unless there exists a slow crossover to $i^{1.0}$, (iii) the effective cluster-size-distribution exponent $\tau$ has a value closer to 2.0 than 1.5, and (iv) if the probability that two clusters will join depends on their mobility, then a value of $\tau$ less than 1.5 might be expected.

• Received 11 May 1987

DOI:https://doi.org/10.1103/PhysRevA.36.5498