Stretching vibrations of benzene molecule in the nonlinear model

A five-parameter nonlinear model is introduced to the description of the st retching vibrational modes of benzene molecule in the electronic ground sta te, and is applied for the first time to the calculations of energy levels of C-H and C-D stretches of C6H6 and C6D6 in vapor phase. The results obtai ned agree well with the experimental vibrational energy levels and with the results obtained from other model calculations. Moreover, our model calcul ations predict accurately some new overtone and combination bands that have not been studied experimentally.