Vibrational spectra and non linear optical proprieties of l-histidine oxalate: DFT studies

► In this study, l-histidine oxalate crystallizes in the space group P212121 of orthorhombic system. ► All the experimental vibrational bands have been discussed and assigned to normal mode. ► The non linear optical properties of l-histidine oxalate have been investigated by DFT method. ► The results indicate hydrogen bonding increased the hyperpolarizability of the crystal.