Experimental

R factor = 0.037; wR factor = 0.092; data-to-parameter ratio = 16.4. In the crystal structure of the title compound, C8H20N C4H5O6 2H2O, the ions and water molecules are linked via O—H O and C—H O hydrogen bonds, forming a two-dimensional network parallel to (001). Related literature For hydrogen-bond motifs, see: Bernstein et al. (1995). For related structures, see: Allen et al. (2006); Jiang et al. (2008); Mei et al. (2002)