Diaqua-bis(2-methyl-1H-imidazol-3-ium-4,5-dicarboxyl-ato-κO,O')magnesium.

The title compound, [Mg(C(6)H(5)N(2)O(4))(2)(H(2)O)(2)], was prepared by reaction of Mg(NO(3))(2) and 2-methyl-1H-imidazole-4,5-dicarboxylic acid under hydro-thermal conditions. The Mg(II) atom lies on an inversion centre and displays a distorted octa-hedral coordination geometry. An extended three-dimensional network of inter-molecular O-H⋯O and N-H⋯O hydrogen bonds stabilizes the crystal structure.