The spatial correlations of Abell clusters

It is demonstrated that the simple calculation of the cluster-cluster correlation function performed by previous authors suffers from a systematic error out to distances of order 15 to 20h-1 Mpc. This causes the model predictions to be overestimates of the actual enhancement of cluster-cluster over galaxy-galaxy correlations. Rigorous calculations of peak-peak correlations are necessary if the biasing model is to be evaluated. (author)