The present article reports the growth of single crystals of a complex Orthonitroaniline with picric acid (2[C6H6N2O2]center dot C6H2(NO2)(3)OH) (ONAP) by solution growth (slow evaporation) method at room temperature. Single crystal XRD, UV-vis spectral analysis and TGA/DTA studies were carried out. FT-IR and Raman spectra were recorded to explore information of the functional groups. The high-resolution X-ray diffraction curve reveals the internal structural low angle boundaries. The PL spectrum of the title compound shows green emission. Dielectric behaviour was investigated at 33 and 70 degrees C. The dipole moment and first-order hyperpolarizability (beta) values were evaluated by using Gaussian 98 W software package with the help of B3LYP the density functional theory (DFT) method. The possible modes of vibrations are theoretically predicted by factor group analysis. The mechanical stability of the grown crystal was tested with Vicker's microhardness tester and the work hardening coefficient of the grown material was estimated. (C) 2010 Elsevier B.V. All rights reserved.