The first attempts to improve sampling consisted of running a series of MTD runs in xtb with different values of the kpush and alpha settings, then processing the ensembles with the screen function of CREST. These runs were initiated from the lowest-energy structure b) a) provided by the initial CREST computation. CREST uses kpush between 0.1688 E h and 1.125 E h in standard runs, or between 0.1125 E h and 0.225 E h for NCI mode and an alpha between 0.1 bohr -2 and 1.3 bohr -2 for standard runs, or between 0.25 bohr -2 and 1.0 bohr -2 for NCI mode. It was already clear from the examination of trajectories that the NCI mode biasing was more energetic than desired, as evidenced by the rapid disruption of hydrogen bonds and π -π stacking. Thus, a range of kpush values, between 0.015 and 0.1 E h , and a range of alpha values, between 0.8 and 3.1 bohr -2 were tested. It is possible that increasing tdump, the interval at which new potentials are added, could also satisfactorily reduce the energetics of the simulation and allow enough time for equilibration and exploration between adding new potentials, however, this option was not explored. It was found that kpush values of 0.05 or 0.015 E h and alpha values of 1.3 or 3.1 bohr -2 gave the greatest number of lowenergy conformers for the case of the 1 2 -2a trimer in a 30 ps run. These values were then adopted for all subsequent runs. All test runs improved on the energy of the structure determined via standard NCI mode in CREST by 11.9 kcal/mol (50 kJ/mol) or more. This result was very encouraging, but attempts to continue improving the energy by starting a new cycle from the best energy conformer found were unsuccessful. Although lower energy conformers had been found, the global minimum had not yet been located, since by starting CREST from a variety of other starting structures, at least one minimum 1.0 kcal/mol (4.3 kJ/mol) lower in energy had been located previously.