Application of computational techniques on non-covalent interactions, H-bond nature of monomeric and dimeric form of crystal structures, and topological insights of glycine glutaric acid

This study utilizes DFT to investigate and optimize the structure of Glycine Glutaric acid (GGA) crystal in both monomer and dimer forms, assessing its electronic and optical properties. Relaxed PES scanning identified potential conformers within the COOH and NH₂ functional groups. FT-IR spectrum confirmed these groups and simulated spectra were correlated with the experimental data. The stable monomer was selected for detailed analysis of electronic charge transfer using MEP, FMOs, and UV–visible absorbance spectra. Non-covalent interactions, primarily O–H⋯O and N–H⋯O hydrogen bonds, were explored using optimized structures. Solvent effects, analyzed via the IEFPCM method, revealed heightened reactivity in the aqueous phase. Topological studies (AIM, LOL, ELF, and RDG) and Hirshfeld surface analysis were applied to understand inter and intramolecular contacts, with crystal packing dominated by O⋯H/H⋯O interactions contributing to 63.4 % efficiency. As per DFT prediction, the GGA exhibits strong NLO potential due to significantly higher polarizability and hyperpolarizability ($⟨\beta ⟩=$ 1.3618 × 10⁻³⁰ e.s.u.) indicating promising nonlinear optical properties.