A single crystal of gamma-glycine (GG), a polymorph of glycine, was synthesized by crystallization. The single crystal of GG was grown from an aqueous solution. The morphology of GG was studied in order to assess its growth facets. The good quality single crystals were subjected to X-ray diffraction studies to reveal their structure. The FT-IR spectral analysis was carried out to confirm the presence of expected functional groups. The UV-Vis analysis was done for GG single crystals to determine the optical transparency and band gap. Simultaneous TG-DTA analysis was employed to understand the thermal and physicochemical stability of the title compound. The mechanical stability and laser stability of GG single crystal were studied using Vickers microhardness test and laser induced damage threshold on different planes of the crystal to reveal its anisotropic nature. The dielectric measurement was carried out as a function of frequency and the results were discussed. The existence of second harmonic generation (SHG) of the title compound was confirmed by Kurtz-Perry powder technique. The SHG effective nonlinearity and particle size dependence of GG powder sample were compared with a standard reference material: potassium dihydrogen phosphate (KDP).

Optically transparent good quality single crystal of 3-Aminonitrobenzene (3-ANB) was grown by slow evaporation technique using methanol as solvent. The grown crystal was subjected to single crystal X-ray diffraction analysis in order to reveal its cell parameters, crystal structure and space group. Powder X-ray diffraction analysis was carried out in order to verify the crystalline nature. UV-Vis study was carried out to measure the optical transparency of the title material and also optical band gap was determined from the transmittance window. The existence of second harmonic generation (SHG) in the title material was confirmed by Kurtz–Perry powder technique. In order to throw light on the crystal structure, linear and nonlinear optical properties at molecular level, Density Functional Theory (DFT) was employed using B3LYP/6[Formula: see text]G (d, p) level of basis set. The DFT study illustrates the HOMO–LUMO energy gap analysis and the existence of SHG behavior of 3-ANB at molecular level.