2-{3-[2-(4-dimethylaminophenyl)vinyl]-5,5-dimethylcyclohex-2-enylidene}-malonitrile (DAT2) is a potential candidate for generating Terahertz radiation in the range 0.1-3 THz. In the present work, we synthesized DAT2 compound and confirmed it's molecular structure by proton NMR. Good quality single crystals of DAT2 of size 1.2?0.5? 0.2 cm3 are grown for the first time, using solvent evaporation technique. The grown crystals are tested for crystalline perfection using powder XRD study and the crystal structure is determined to be monoclinic with centrosymmetric space group P21/C. The electronic band structure was studied by Density Functional Theory and the theoretical band gap was compared with experimental bandgap 1.6 eV. Further,using DFT the dielectric constants εr(ω) andεi(ω), reflectivity R(ω), refractive index n(ω), extinction coefficient K(ω), optical conductivity σ(ω) and energy loss function L(ω) for DAT2 crystal has been calculated. The results are discussed in detail ABSTRACT 2-{3-[2-(4-dimethylaminophenyl)vinyl]-5,5-dimethylcyclohex-2-enylidene}-malonitrile (DAT2) is a potential candidate for generating Terahertz radiation in the range 0.1-3 THz. In the present work, we synthesized DAT2 compound and confirmed it's molecular structure by proton NMR. Good quality single crystals of DAT2 of size 1.2×0.5× 0.2 cm 3 are grown for the first time, using solvent evaporation technique. The grown crystals are tested for crystalline perfection using powder XRD study and the crystal structure is determined to be monoclinic with centrosymmetric space group P 2/C. The electronic band structure was studied by Density Functional Theory and the theoretical band gap was compared with experimental bandgap 1.6 eV. Further,using DFT the dielectric constants [ε ρ (ω ) andε ι (ω )], reflectivityR (ω ), refractive index n (ω ), extinction coefficient K (ω ), optical conductivity σ (ω ) and energy loss function L (ω ) for DAT2 crystal has been calculated. The results are discussed in detail Index terms: nonlinear optical material. organic compound. crystal growth DFT study. dielectric constant. refractive index