Quantum computational investigation into structural, spectroscopic, topological and electronic properties of L-histidinium-L-tartrate hemihydrate: Nonlinear optical organic single crystal.

For the first time, a systematic investigation of optimization in the geometrical, vibrational, natural bonding orbital (NBO), electronic, linear and nonlinear optical properties, and Hirshfeld surface analysis for the L-histidinium-l-tartrate hemihydrate (HT) crystal is reported by employing the density functional theory (DFT). The geometrical parameters and vibrational frequencies obtained from the B3LYP/6-311++G(d,p) level of theory are in good agreement with the experimental values. The presence of strong hydrogen bonding interactions in the molecule causes an intense absorption peak in the infrared spectrum below 2000 cm.