Analysis of vibrational spectra and nonlinear optical properties of organic molecule l-alaninium formate

► The growth and the vibrational spectral analysis of LAF crystals taken up to understand the NLO activity. ► Hydrogen bonding and charge transfer interactions are also analyzed. ► The calculated first hyperpolarizability of BPH is found to be 2.84 × 10−30 esu, which is 2 times that of KDP. ► The red shifting of O-H stretching wavenumber confirms the intramolecular O-H⋯O hydrogen bonding.