Bis[(1Z,2E)-N-(2,6-diethylpheny1)-N'-hydroxy-2-(hydroxyimino)acetimidamidato]nickel(II) was synthesized and characterized by IR, UV Vis, and X-ray diffraction technique. The molecular geometry and vibrational wavenumbers of the complex were computed using the density functional (B3LYP) method with the LanL2DZ basis set. The optimized geometric parameters and vibrational frequencies show good consistency with the experimental data. Electronic absorption spectra of the complex have been calculated using the time -dependent density functional theory (TD-DFT) method at the same level. Additionally, using the integral equation formalism of the polarisable continuum model, solvent effects were computed and compared experimental one. In order to explore the nonlinear optical properties, the polarizability and first hyperpolarizability were also performed theoretically. Besides, frontier molecular orbitals, molecular electrostatic potential, and thermodynamic properties were performed at B3LYP/ LanL2DZ level. (C) 2017 Elsevier B.V. All rights reserved.