Fig. 2. Comparison of the structural models obtained by different methods using 3DED data.

a The refined reference structural model obtained by the dual-space method. The structural models were obtained using b SA, c charge flipping, and d classic direct method with 0.9 Å resolution. The structural models were obtained using e dual-space method, f SA, g charge flipping, and h classic direct method with 1.5 Å resolution. D₁ and D₂ indicate the distances between the N atoms; the D₃, D₄, D₅, and D₆ are the C … C bond distances between two fragments; the A₁, A₂, A₃, A₄, A₅, A₆, A₇, and A₈ are the bond angles involving C atoms from two fragments in the phenyl rings. Gray spheres: C; blue spheres: N; red spheres: O.