The similarity between individual pairs of USRCAT descriptors is canonically calculated by the USRscore , a special variant of the Manhattan distance. In line with the use of USRscore for USRCAT descriptors, we use the Canberra distance , which is a weighted version of the Manhattan distance, to calculate the similarity between individual pairs of Zernike descriptors. For use in the descriptor-based rediscovery benchmarks presented in this paper, we propose using a conformer-aggregated similarity metric S which, with respect to the target molecule, is defined as