A simple hydrated salt with a complex hydrogen-bonding network: tetrakis(5-amino-3-carboxy-4H-1,2,4-triazol-1-ium) hexachloridocadmate(II) tetrahydrate.

In the title cadmium chloride salt, (C3H5N4O2)4[CdCl6]·4H2O, the asymmetric unit comprises two N-protonated 5-amino-3-carboxy-4H-1,2,4-triazol-1-ium cations, half a [CdCl6](4-) anion and two molecules of water. The Cd(2+) cation is located on a centre of inversion and is coordinated by six chloride anions, forming a distorted octahedron. In the crystal structure, alternating layers of cations and anions are arranged along the [101] direction, forming a three-dimensional supramolecular network via a combination of hydrogen-bonding and aromatic stacking interactions.