The poor results for NTO are not fully understood. Although the choice of force field and electrostatic model was not found to influence the average CSP performance across all EMs, we observed that the results for individual molecules could be sensitive to the choice of force field. For example, CSP using the W99rev force field with B3LYP/6-311G** provided a match to the experimental β-NTO crystal structure with an RMSD 30 of 0.281 Å (see SI for more detail) and a relative energy of 1.98 kJ mol -1 .