To generate the projections, the Smooth Overlap of Atomic Positions (SOAP) descriptor was evaluated on all of the structures. In addition to the local SOAP descriptor for each atomic site, a global SOAP descriptor is constructed by averaging the atomic neighbour density expansion coefficients over the atomic sites before the rotationally invariant power spectrum is calculated. This procedure yields a description of the global structure that is more informative than a naive average of local SOAP descriptors across the atom sites. All descriptor instances were normalized to have unit norm.