VIBRONIC DEPHASING OF ANHARMONIC MOLECULES .2. IMPURITY MOLECULES ISOLATED IN LOW-TEMPERATURE MATRICES

The quantum-mechanical theory of vibronic dephasing presented in the first paper of this series is applied to the case of a diatomic impurity dissolved in a solid rare-gas host. An explicit expression for the pure dephasing rate T'2-1 is derived in terms of microscopic properties of the impurity and host, and the effects of variations in the parameters characterizing these properties are investigated. The expression for T' 2-1 is applied specifically to the system Cl 2/Ar in order to relate the results to those of previous classical-trajectory calculations and of experimental measurements. The significance of anharmonicity in the intramolecular potential curve (of the impurity) is demonstrated. © 1979 American Institute of Physics.