Molecular structure, vibrational spectra, first hyperpolarizability and HOMO-LUMO analysis of p-acetylbenzonitrile using quantum chemical calculation

► Natural bond orbital (NBO) used to elucidate inter-, intra- molecular interactions. ► NLO of the material is confirmed by the first hyperpolarizability caculations. ► electronegativity, chemical hardness and electrophilicity index were calculated. ► NBO atomic charges confirm the site of intramolecular interaction. ► Combined experimental and theoretical wavenumbers are assigned to various modes of vibrations.