Growth, characterisation and DFT investigations on 3-hydroxy-6- methyl -2- nitropyridine (3H6M2NP)-A novel third order nonlinear optical material

•The grown 3H6M2NP crystal belongs to Orthorhombic crystal system with centrosymmetric space group Pbca..•TG/DTA analysis reveals the grown crystal melting point as 182 °C and Photoluminescence spectrum shows UV emission.•The third order nonlinear optical susceptibility (χ3) = 2.616 × 10−8 esu was calculated using Z-Scan technique.•The hyper polarizability value of 3H6M2NP is found to be 2.9 times larger than that of the urea.•The molecular structure of 3H6M2NP was optimised and all ab initio calculations were done theoretically. Single crystals of nitropyridine derivative 3-hydroxy-6-methyl-2-nitropyridine was grown by slow evaporation solution growth technique using ethanol. 3H6M2NP was crystallized in orthorhombic crystal system with centrosymmetric space group Pbca. The crystalline nature, presence of functional groups and its vibrational modes were assigned using FT-IR and FT-Raman spectroscopic techniques. The UV–Vis spectrum reveals 3H6M2NP crystal is transparent in the visible region with lower cut-off wavelength. The luminescence properties were confirmed by PL spectrum and 3H6M2NP crystal exhibited thermal stability up to 182 °C. The molecular structure of 3H6M2NP was optimised and all ab initio calculations were done theoretically. From Z-scan technique, the third order nonlinear optical susceptibility of the grown crystal was found to be χ3 = 2.616 × 10−8 esu. The hyper polarizability value was found to be 2.9 times larger than that of the urea which settles the NLO activity.