Notes. The column ‘N clusters’ lists how many clusters have been joined to form the substructure. The ‘N members’ entry gives the total number of core members in all participating clusters (according to a Mahalanobis distance cut of 2.13 to each of these clusters), and within parentheses the total number of stars in the data set that are assigned to the substructure after a second Mahalanobis distance cut of 2.13 to the structure. μ is the centroid of the structures defined from the original cluster members, where indices 0 to 2 reflect E, L_⊥, and L_z in the scaled IoM space (see Paper I). Each σ_ij represents the corresponding entries in the covariance matrix. Equations (3) and (4) can be used to transform the means and the elements of the covariance matrix to physical units, respectively.