Quantum Chemical Determination of the Molecular Structure of 1,2,4-Triazole and the Calculation of its Infrared Spectrum

The molecular structure of 1,2,4-triazole is calculated by the density functional theory method in the B3LYP/6–31G approximation using the Gaussian program package. The calculated bond lengths and bond angles are well consistent with their experimental values. The results of the calculation show that triazole has a planar structure. Normal vibrational frequencies of triazole are calculated and these normal vibrations are assigned. Absorption band intensities are calculated and the IR spectrum of triazole is constructed. When compared, the theoretical spectrum qualitatively reproduces the experimental one.