Figure 1.

Schematic of current and proposed CSP-NMRX methods. (a) An example of a successful structure prediction using the current CSP-NMRX method. (b) An example of a failed structure prediction using the current CSP-NMRX method. (c) An example of the proposed experimentally constrained CSP-NMRX method, which successfully overcomes the failure of the current CSP-NMRX method shown in panel (b). In each panel the structures in the first line depict single-molecule gas-phase conformations sorted by their conformational energy. After application of a given selection criterion, a reduced conformer set is used to generate an ensemble of possible crystal structures (represented by the second line in each panel). The colored boxes are intended as a guide to the eye as to which conformer results in which crystal structures. The third line in each panel represents crystal structures picked from the second line after a further selection criterion is applied. This final set of structures is then compared to the experimental chemical shifts to determine the correct crystal structure. In each panel, the scatter plot shows the experimental ¹H chemical shift plotted against the DFT-calculated ¹H chemical shift for the trial structure with the lowest error between DFT and experimental chemical shifts.