Vibration–Translational Energy Transfer According to the Morse Potential

Abstract

A quantum‐mechanical analysis of molecular vibration–translational motion energy transfer is obtained using the Morse potential, a one‐dimensional model, and the method of distorted waves. All wavefunctions and transition matrix elements are obtained in closed form. In the limit of high temperatures, the results are identical to the Landau–Teller expression. At low temperatures, resonances are found to result from the attractive part of the molecular interaction which can lead to transition probabilities that increase with decreasing temperature. The theory is compared with experimental data for the deactivation of O₂ by various collision partners. The agreement is excellent, though some uncertainty in the interaction well depths is found due to a lack of very low‐temperature data. A comparison with the results of classical and semiclassical theories is given.