A new semiorganic nonlinear optical thiourea potassium magnesium sulphate (TPMS) crystal was synthesized. TPMS single crystals were grown from aqueous solution by slow evaporation technique. The solubility of TPMS was determined for various temperatures. Single crystal X-ray diffraction (XRD) study was carried out to identify the lattice parameters. Various diffracting planes of the grown crystal were identified from the powder X-ray diffraction study. Fourier transform infrared (FT-IR) studies confirm the various functional groups present in the grown crystal. The transmission spectrum of this crystal shows that the lower cut off wavelength lies at 224 nm. The thermal analysis confirmed that the crystal is stable up to 223°C. Microhardness studies revealed that the hardness of the grown crystal increases with an increase in load. The nonlinear optical (NLO) property of the grown crystal has been confirmed by Kurtz powder second harmonic generation (SHG) test.
