Connecting the Dunham Expansion to the Dissociation Limit for Interatomic Potentials: Application to Lennard-Jones m–n Potentials
| Autor: | Randall B. Shirts |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Mechanical equilibrium
010304 chemical physics Chemistry 010402 general chemistry 01 natural sciences Diatomic molecule Dissociation (chemistry) 0104 chemical sciences law.invention law 0103 physical sciences Physics::Atomic and Molecular Clusters Physics::Chemical Physics Physical and Theoretical Chemistry Atomic physics |
| Zdroj: | The Journal of Physical Chemistry A. 122:8591-8599 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/acs.jpca.8b08095 |
| Popis: | Dunham generated the expansion for energy levels of a rotating, vibrating diatomic molecule from an expansion of the potential about the equilibrium position. For partition functions, however, the energy levels are needed all the way to dissociation. Analytic Morse oscillator energies are not very useful because the exponential decay of the Morse potential is much too short-ranged for any physical system. The longer-range Lennard-Jones 12-6 potential could be used, but quantum energies have not previously been conveniently fit. I show how Dunham coefficients begin a set of asymptotic functions for any interaction potential, one function arising from each successive term in the WKB expansion. I apply this to the family of Lennard-Jones m- n (LJ m- n) potentials with an R |
| Databáze: | OpenAIRE |
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