Diglycine Barium Chloride Monohydrate have been synthesized and characterized by the 13C and 1H NMR spectroscopy and single crystal X-ray structural studies with a detailed analysis of Hirshfeld surface and fingerprint plots facilitating the interactions within the crystal structure. The Protonated N–H⋯O and intermolecular interaction responsible for the NLO activity are studied using DFT studies as well as experimental spectroscopic techniques. The molecular geometry, first & second hyperpolarizability studies and harmonic vibrational wavenumbers were calculated using density functional theory with B3LYP/SDD methods. The detailed interpretation of the vibrational spectra (FTIR and Raman) was carried out with the Normal Coordinate Analysis (NCA) following the scaled quantum mechanical force field methodology. The inter and intra molecular interactions responsible for the stabilization of the molecule were revealed by the NBO and AIM analyses. Photoluminescence spectrum shows that the luminescence is at the blue region. The observed saturable absorption and self-defocusing effect lead to optical limiting action at 532 nm for a CW diode-pumped Nd: YAG laser (50 mW) beam. Optical nonlinearity studies (z-scan) give the nonlinear refractive index, nonlinear absorption coefficient, third order nonlinear susceptibility, second order hyperpolarizability and optical limiting. The obtained results indicate that the synthesised compound is a good candidate for optical limiting and OLED applications. © 2018 Elsevier Ltd