CLASSICAL MODEL FOR THE STUDY OF ISOTOPE EFFECTS IN ENERGY EXCHANGE AND PARTICLE EXCHANGE REACTIONS
An idealized model of a collinear collision between a diatomic molecule AD and an atom C was studied. The threeatom potential-energy surface is an L- shaped region consisting of two flat-bottomed troughs with vertical walls; and the rectangular corner region of the L is at a higher uniform potential. The dependence of the classical energy exchange probability on the relative masses of the three particles is investigated systematically for this model. All possible collisions are considered in which the initial distribution of energy between the vibrational and relative translational components is fixed. Formulas are derived that express the average fraction of vibrational energy after collision as a function of the fraction of vibrational energy before collision. In the reaction AB + C yields A + BC, the dependence of the classical particle-exchange probability on the relative mass of Particles A and C is determined in the limiting case where the mass of Particle B is infinite. In addition to the relative mass parameter, the particle exchange probability depends upon the initial vibrational and relative translational energies and the height of the potential barrier in the corner region V/sub II/. A thermal average probability for particle exchange is determined that depends upon two parameters: the relative mass of A and C and V/sub II//kT. This dependence on the relative mass, an isotope effect, is a product of classical mechanics. (auth)
- Research Organization:
- National Bureau of Standards, Washington, D.C.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-18-012080
- OSTI ID:
- 4119209
- Journal Information:
- Journal of Chemical Physics (U.S.), Vol. Vol: 40; Other Information: Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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