Finally, we note that, as with the independent, fixedlength QR-BH results, the optimal basin hopping temperature differs among space groups (Table ). For the more challenging XAFQAZ co-crystal, high temperature leads to more consistent location of the global minima in P 2 1 /c and I4 1 /a, while low temperature gives more consistent results for in space group F dd2. We also tried running QR-BH at T = 0 K (Table ), which allows only BH steps that lower the energy, as well as trying smaller Monte Carlo step sizes. These were both tested to try to keep the BH trajectories more localized on the energy surface by discouraging trajectories from escaping their current energy basin. However, both modifications led to poorer overall efficiency (Table , S7).