The Cluster Members report gives the following:
Cluster
The cluster identifier.
Members
The variables included in the cluster.
RSquare with Own Cluster
The squared correlation of the variable with its cluster component.
RSquare with Next Closest
The squared correlation of the variable with the cluster component for its next closest cluster. The next closest cluster is the cluster for which the squared correlation of the variable with the cluster component is the second highest.
1 - RSquare Ratio
A measure of the relative closeness between the cluster to which a variable belongs and its next closest cluster. It is defined as follows:
(1 - RSquare with Own Cluster)/(1 - RSquare with Next Closest)