Table 4. Bond lengths (Å) obtained by applying the cluster-based S-FFT algorithm to powder diffraction (PD) data and by least-squares refinement from single-crystal (SC) data.

Bonds have been grouped into types: (i) average C—C bond lengths from PD and SC (the former are longer by a factor of 1.035, which may be attributed to the non-inclusion of H atoms in DM); (ii) single and double C—O bonds are correctly assigned with similar average lengths, 1.30 (PD) and 1.27 Å (SC); (iii) distances between hydrogen-bonded O atoms are practically coincident.

Bond type	PD	SC
C—C (single bond) (14×)	1.56 (9)	1.51 (3)
C—C (phenyl ring) (12×)	1.43 (8)	1.38 (2)
C—O (≃ single bond) (2×)	1.50 (3)	1.32 (1)
C—O (≃ double bond) (2×)	1.09 (6)	1.21 (1)
O⋯O (hydrogen bonds) (2×)	2.66 (1)	2.65 (1)