ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We present an analysis based on the quantized version of the effective mass theory and on classical trajectory calculations which leads to an interpretation of all the characteristic features of the striking new phenomenon named rotation-induced quasiresonant vibration–rotation energy transfer and observed recently in Li*2(nvi,Ji) + X → Li*2(nvf,Jf)+ X collision (X=He, Ne, Ar, Xe). The "ordinary branch'' of the effective mass theory reproduces the broad Jf distribution in the nonresonant internal energy transfer found experimentally at lower Ji values (Ji = 8 and 22). The "extraordinary branch'' of the same theory gives the narrow, sharply peaked quasiresonant Jf distributions as observed at Ji values 42 and higher. The conclusions derived from the effective mass theory and classical trajectory calculations enable us to elucidate the celebrated experimental correlations between the most probable changes in the rotational and vibrational quantum numbers, as well as the "locking mechanism'' by which these correlations prevail over large intervals of the initial angular momentum Ji. On the same basis we explain why the total vibrationally inelastic cross section is greatly enhanced by increasing Ji and why the shape of the final Jf distribution is identical (within the experimental uncertainty) for Ne, Ar, and Xe, but not for the He.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.462972
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