To benchmark the packing search protocol, we curated a dataset of 426 neat Z'=1 crystal polymorphs from the CSD drug subset (Table in SI). These crystals are relaxed with symmetry constrained MD using the OPLS4 force field. Good crystal similarity is achieved for the full dataset, demonstrating the accuracy of the OPLS4 in describing molecular crystal packing interactions. The crystal-relaxed ASU is then used to search for the relaxed crystal structure. For the 426 crystals used in this benchmark, a candidate structure matching experiment was generated with close to a 100% success rate (Table Force field parametrization and conformer generation costs are omitted due to minimal computational expense (tens of CPU hours at most).