| Autor: |
Dashevskaya, E. I., Litvin, I., Nikitin, E. E., Troe, J. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 7/2/2018, Vol. 149 Issue 1, pN.PAG-N.PAG, 10p, 4 Charts, 8 Graphs |
| Abstrakt: |
In this paper, the electronically nonadiabatic Landau-Zener (LZ) mechanism for the vibrational relaxation v = 1 → v = 0 of NO ( X 2 Π ) in collisions with Ar ( S 0 1 ) is discussed. It corresponds to nonadiabatic transitions between two crossing vibronic potential energy surfaces (PESs) originating from vibrational states of the collision complex and supported by two coupled electronic PESs. The LZ rate coefficients k 10 LZ are calculated within the uniform Airy approach in the reaction coordinate approximation with parameters derived from ab initio PESs and an asymptotic estimation of the Franck–Condon factor in the nonadiabatic coupling region. The rate coefficients are close to the experimental rate coefficients available over the range of 900–2500 K, where the electronically adiabatic Landau-Teller (LT) mechanism with the rate coefficients k 10 LT does not make a noticeable contribution to the total relaxation rate. The ratio k 10 LZ / k 10 LT increases with temperature and the LZ and LT mechanisms have comparable rates at about 4000 K. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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