In our implementation of the ABC algorithm, the atomic positions are characterised by a vector representative of the location and orientation of each cluster in the system. This produces a trial structure. Next, the trial structure is either energetically evaluated using a computational chemistry code or that computational code is used as a driver in a local optimisation (LO). The latter methodology further optimizes all atomic coordinates to obtain the low energy structure. This way the GO provides guess structures for the LO algorithm which results in a reduction in size of the PES and smooths out a lot of unnecessary structures to sample. We provide a comparison of both methodologies in SI section S2.