The ground state structure and NLO properties of hydrazine molecule, metal diamine complex M(NH2)(2) and its derivatives M(NA(2))(2) (M = Be, Mg, Ca and A= Li, Na) are calculated by using different DFT functionals and basis sets. The chosen species are sufficiently stable. The M(NA(2))(2) complexes (A= Li, Na) have rather larger magnitude of third-order response property compared to the hydrazine molecule and M(NH2)(2) complexes. The sum-over-state (SOS) calculated one-photon and two-photon part of second-hyperpolarizability showed almost identical pattern of variation as obtained in the DFT calculated results. The largest second-hyperpolarizability is predicted for the complex Ca(NNa2)(2). (C) 2015 Elsevier B.V. All rights reserved.