Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1O⋯O2i	0.87 (4)	1.94 (4)	2.721 (3)	148 (4)
O2—H2O⋯O1	0.94 (5)	1.79 (4)	2.721 (3)	169 (4)

Symmetry code: (i) .