Effects Due to More Complex Potential-Energy Surfaces

Mass effects do not always predominate. In the vibrational deexcitation of CO(i =l p=0), He is far more effective than Ne in direct contradiction of (10.8). Here the model potential of Fig. 10.5 is far from appropriate the details of the interaction are significant and vibrational quantization is very important. 

Effects Due to More Complex Potential-Energy Surfaces 

If the interaction were repulsive (Zl 0), the inelasticity would decrease if E, the relative A-BC translational energy, is less than zl, the particle cannot overcome the barrier and is reflected at the discontinuity. 

If A is preferentially attracted to B, assume the attraction is to B alone and modify the potential surface by introducing a step at constant as shown in Fig. 10.7b. For the initial conditions shown the particle is refracted upon entering the well, reflected at wall 1, and refracted again upon leaving the well. Geometric considerations show that the well has not altered the energy transfer. The inelasticity is still given by (10.7) and (10.8). 

The other limiting case occurs when A is attracted to C, which can be modeled by incorporating a potential well with a discontinuity at a constant separation as shown in Fig. 10.7c. The inelasticity calculations 

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Sec. 10.4 Effects Due to More Complex Potential-Energy Surfaces 333... 

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