Abstract
The title complex, (NH(4))(2)[Co(C(3)H(3)O(4))(2)(H(2)O)(2)]·2H(2)O, features a six-coordinate Co atom located on a center of symmetry. The octa-hedral O(6) coordination geometry is defined by two bidentate malonate ligands and two water mol-ecules, with the latter in a trans configuration. The mol-ecules are linked through O-H⋯O and N-H⋯O hydrogen-bonding inter-actions, forming a three-dimensional supra-molecular network.