NiCl2(H2O)(C12N2H8) was synthesized in solution and its structure was studied by single-crystal X-ray diffraction. It crystallizes in the monoclinic system (S. G.: P2(1)/n), Z = 4, with the cell parameters (angstrom, degrees): a = 12.6640(5), b = 6.8322(3), c = 14.2054(5) and beta = 93.569(3). The final residual factors of the refined structure model R/Rai were 0.031/0.082 for 2156 independent reflexions and 172 parameters. The crystal structure is described in terms of Ni2Cl4(H2O)(2)(Phen)(2) dimmers interacting through weak intermolecular O-H center dot center dot center dot Cl Hydrogen bonds. The 2D fingerprint plots, built using the Hirshfeld surface analysis, helped analyzing and quantifying all the intermolecular contacts and revealed the main intermolecular interactions around the title complex. The computational investigation was undertaken at M06-2X/6-31G(d)(LANL2DZ) level by using Gaussian. (C) 2020 Elsevier B.V. All rights reserved.