IR spectroscopic study, HOMO-LUMO, NBO analysis, and some calculations on H2O, H2S, H2Se and H2Te by density functional method

In this investigation، IR spectroscopy، HOMO-LUMO analysis، NBO analysis، polarity determination، bond length، bond angle، natural charge of atoms، hardness، Softness، electrophilicity index and chemical potential from H2O to H2Te are calculated. DFT (Density Functional Theory) calculations with methods (PBEPBE and HCTH) and DGDZVP basis set were performed. According to the calculations، polarizability increases from H2O to H2Te and the HOMO–LUMO energy gap decreases. Using IR spectroscopy، vibrational active modes of the compounds have been studied. The vibrational frequencies decreases from H2O to H2Te due to the increase in bond length.